Answer:
1 [tex]\sigma_{\= x } = 0.0130[/tex]
2 [tex]n = 3908.5[/tex]
Step-by-step explanation:
From the question we are told that
The sample size is [tex]n_p = 1400[/tex]
The number of those that said the would use internet is [tex]k = 872[/tex]
The margin of error is [tex]E = 0.02[/tex]
Generally the sample proportion is mathematically evaluated as
[tex]\r p = \frac{k}{n_p}[/tex]
substituting values
[tex]\r p = \frac{ 872}{1400}[/tex]
substituting values
[tex]\r p = 0.623[/tex]
Generally the standard error of [tex]\r p[/tex] is mathematically evaluated as
[tex]\sigma_{\= x } = \sqrt{\frac{\r p (1- \r p)}{n} }[/tex]
substituting values
[tex]\sigma_{\= x } = \sqrt{\frac{0.623 (1- 0.623)}{1400} }[/tex]
[tex]\sigma_{\= x } = 0.0130[/tex]
For a 95% confidence interval the confidence level is 95%
Given that the confidence interval is 95% the we can evaluated the level of confidence as
[tex]\alpha = 100 - 99[/tex]
[tex]\alpha = 1\%[/tex]
[tex]\alpha = 0.01[/tex]
Next we obtain the critical value of [tex]\frac{\alpha }{2}[/tex] from normal distribution table (reference math dot armstrong dot edu) , the value is
[tex]Z_{\frac{\alpha }{2} } = 2.58[/tex]
Give that the population size is very large the sample size is mathematically represented as
[tex]n = [ \frac{Z_{\frac{\alpha }{2} ^2 * \r p ( 1 - \r p )}}{E^2} ][/tex]
substituting values
[tex]n = [ \frac{2.58 ^2 * 0.623 ( 1 -0.623 )}{0.02^2} ][/tex]
[tex]n = 3908.5[/tex]
Researchers recorded that a certain bacteria population declined from 120,000 to 200 in 36 hours. At this rate of decay, how many bacteria will there be in 31 hours? Round to the nearest whole number.
Answer: There will 486 bacteria in 31 hours.
Step-by-step explanation:
The population decay in bacteria is exponential.
Exponential function : [tex]y=Ab^x[/tex], where A = initial population, b multiplication decay factor, t= time:
As per given:
Initial population: [tex]A=120,000[/tex]
After 36 hours, population = [tex]120000(b^{36})=200[/tex]
Divide both sides by 120,000 we get
[tex]b^{36}= 0.00167[/tex]
Taking natural log on both sides , we get
[tex]36\ln b=\ln 0.00167\\\\\Rightarrow\ b=e^{\left(\frac{\ln0.00167}{36}\right)}=0.83724629\approx0.8372[/tex]
At x= 31,
[tex]y=120000(0.8372)^{31}=120000\times0.00405234\approx486[/tex]
Hence, there will 486 bacteria in 31 hours.
Let the following sample of 8 observations be drawn from a normal population with unknown mean and standard deviation:
21, 14, 13, 24, 17, 22, 25, 12
Required:
a. Calculate the sample mean and the sample standard deviation.
b. Construct the 90% confidence interval for the population mean.
c. Construct the 95% confidence interval for the population mean
Answer:
a
[tex]\= x = 18.5[/tex] , [tex]\sigma = 5.15[/tex]
b
[tex]15.505 < \mu < 21.495[/tex]
c
[tex]14.93 < \mu < 22.069[/tex]
Step-by-step explanation:
From the question we are are told that
The sample data is 21, 14, 13, 24, 17, 22, 25, 12
The sample size is n = 8
Generally the ample mean is evaluated as
[tex]\= x = \frac{\sum x }{n}[/tex]
[tex]\= x = \frac{ 21 + 14 + 13 + 24 + 17 + 22+ 25 + 12 }{8}[/tex]
[tex]\= x = 18.5[/tex]
Generally the standard deviation is mathematically evaluated as
[tex]\sigma = \sqrt{\frac{\sum (x- \=x )^2}{n}}[/tex]
[tex]\sigma = \sqrt{\frac{\sum ((21 - 18.5)^2 + (14-18.5)^2+ (13-18.5)^2+ (24-18.5)^2+ (17-18.5)^2+ (22-18.5)^2+ (25-18.5)^2+ (12 -18.5)^2 )}{8}}[/tex]
[tex]\sigma = 5.15[/tex]
considering part b
Given that the confidence level is 90% then the significance level is evaluated as
[tex]\alpha = 100-90[/tex]
[tex]\alpha = 10\%[/tex]
[tex]\alpha = 0.10[/tex]
Next we obtain the critical value of [tex]\frac{ \alpha }{2}[/tex] from the normal distribution table the value is
[tex]Z_{\frac{ \alpha }{2} } = 1.645[/tex]
The margin of error is mathematically represented as
[tex]E = Z_{\frac{ \alpha }{2} } * \frac{\sigma }{\sqrt{n} }[/tex]
=> [tex]E =1.645 * \frac{5.15 }{\sqrt{8} }[/tex]
=> [tex]E = 2.995[/tex]
The 90% confidence interval is evaluated as
[tex]\= x - E < \mu < \= x + E[/tex]
substituting values
[tex]18.5 - 2.995 < \mu < 18.5 + 2.995[/tex]
[tex]15.505 < \mu < 21.495[/tex]
considering part c
Given that the confidence level is 95% then the significance level is evaluated as
[tex]\alpha = 100-95[/tex]
[tex]\alpha = 5\%[/tex]
[tex]\alpha = 0.05[/tex]
Next we obtain the critical value of [tex]\frac{ \alpha }{2}[/tex] from the normal distribution table the value is
[tex]Z_{\frac{ \alpha }{2} } = 1.96[/tex]
The margin of error is mathematically represented as
[tex]E = Z_{\frac{ \alpha }{2} } * \frac{\sigma }{\sqrt{n} }[/tex]
=> [tex]E =1.96 * \frac{5.15 }{\sqrt{8} }[/tex]
=> [tex]E = 3.569[/tex]
The 95% confidence interval is evaluated as
[tex]\= x - E < \mu < \= x + E[/tex]
substituting values
[tex]18.5 - 3.569 < \mu < 18.5 + 3.569[/tex]
[tex]14.93 < \mu < 22.069[/tex]
What is the probability that a student who has no chores has a curfew ?
Answer:
15/22
Step-by-step explanation:
Of the 66 students who have no chores, 45 have a curfew. So the probability is 45/66 = 15/22.
what number should replace the question mark
Answer: The missing number is 5.
Step-by-step explanation:
In the table we can only have numbers between 1 and 9,
The pattern that i see is:
We have sets of 3 numbers.
"the bottom number is equal to the difference between the two first numers, if the difference is negative, change the sign, if the difference is zero, there goes a 9 (the next number to zero)"
Goin from right to left we have:
9 - 6 = 3
6 - 2 = 4
4 - 9 = - 5 (is negative, so we actually use -(-5) = 5)
4 - 4 = 0 (we can not use zero, so we use the next number, 9)
3 - 3 = 0 (same as above)
? - 1 = 4
? = 4 + 1 = 5
The missing number is 5.
a student ran out of time on a multiple choice exam and randomly guess the answers for two problems each problem have four answer choices ABCD and only one correct answer what is the probability that he answered neither of the problems correctly
Answer:
The probability that he answered neither of the problems correctly is 0.0625.
Step-by-step explanation:
We are given that a student ran out of time on a multiple-choice exam and randomly guess the answers for two problems each problem have four answer choices ABCD and only one correct answer.
Let X = Number of problems correctly answered by a student.
The above situation can be represented through binomial distribution;
[tex]P(X=r)=\binom{n}{r}\times p^{r}\times (1-p)^{n-r};x=0,1,2,3,....[/tex]
where, n = number of trials (samples) taken = 2 problems
r = number of success = neither of the problems are correct
p = probability of success which in our question is probability that
a student answer correctly, i.e; p = [tex]\frac{1}{4}[/tex] = 0.75.
So, X ~ Binom(n = 2, p = 0.75)
Now, the probability that he answered neither of the problems correctly is given by = P(X = 0)
P(X = 0) = [tex]\binom{2}{0}\times 0.75^{0}\times (1-0.75)^{2-0}[/tex]
= [tex]1 \times 1\times 0.25^{2}[/tex]
= 0.0625
If tanA = 3
evaluate
CosA + sinA\
casA - SinA
Answer:
Hi, there!!!
I hope you mean to evaluate cosA+ sonA /cosA - sinA.
so, i hope the answer in pictures will help you.
2/5×1 3/12? plz help meh
Answer:
[tex]\boxed{\frac{1}{2} }[/tex]
Step-by-step explanation:
Hey there!
Well given,
[tex]\frac{2}{5} * 1 \frac{3}{12}[/tex]
We need to make 1 3/12 improper,
1*12 = 12
12 + 3 = 15
[tex]\frac{2}{5} * \frac{15}{12}[/tex]
2*15 = 30
5*12 = 60
[tex]\frac{30}{60}[/tex]
Simplified
[tex]\frac{1}{2}[/tex]
Hope this helps :)
In parallelogram PQSR, what is PQ? 2 cm 5 cm 6 cm 9 cm
Answer:
D) 9 cm
Step-by-step explanation:
EDGE 2020
(D) 9 cm.
Parallelogram:A simple (non-self-intersecting) quadrilateral with two sets of parallel sides is known as a parallelogram in Euclidean geometry. A parallelogram's facing or opposing sides are of equal length, and its opposing angles are of similar size. The Euclidean parallel postulate or one of its equivalent formulations must be used in order to demonstrate the congruence of opposed sides and opposite angles because both conditions are a direct result of this postulate.In contrast, a quadrilateral with only one set of parallel sides is referred to as a trapezoid or trapezium in British or American English.The parallelepiped is a parallelogram's three-dimensional equivalent.Therefore, the correct answer is (D) 9 cm.
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How would you find the coefficient of the third term in (x+5)^7?
Answer:
The answer is option B
Step-by-step explanation:
To find the coefficient of the third term in
[tex](x + 5)^{7} [/tex]
Rewrite the expansion in the form
[tex](a + x)^{n} [/tex]
where n is the index
So we have
[tex] ({5 + x})^{7} [/tex]
After that we use the formula
[tex]nCr( {a}^{n - r} ) {x}^{r} [/tex]
where r is the term we are looking for
For the third term we are looking for the term containing x²
that's
r + 1 = 3
r = 2
So to find the coefficient of the third term
We have
[tex]7C2[/tex]
Hope this helps you
first of all, the notation is wrong it should be [tex] {}^nC_r \text{ and more usual notation is } {n \choose k} [/tex]
second, the
[tex](r+1)^{\text{th}} \text{ term } T_{r+1} \text{ in the expansion of } (x+a)^n \text{ is } {n \choose r}x^{(n-r)}a^r[/tex]
here [tex] a=5 \text{ and } n=7 \text{ and for } 3^{\text{rd}} \text{ term } T_3, \quad r+1=3 \implies r=2 [/tex]
so the coefficient of third term is, [tex]{7 \choose 2}={7\choose 5}[/tex]
an important property of binomial coefficient you should know:
[tex] {n \choose k}={n \choose {n-k}}[/tex]
and if you interchange [tex] x \text{ and } a[/tex]
only the "order" will get reversed. i.e. the series will start from back.
another thing, the [tex] k^{\text{th}} \text{ term from beginning, is the } (n-k+2)^{\text{th}} \text{ term from behind}[/tex]
In a recent year, the scores for the reading portion of a test were normally distributed, with a mean of and a standard deviation of . Complete parts (a) through (d) below. (a) Find the probability that a randomly selected high school student who took the reading portion of the test has a score that is less than . The probability of a student scoring less than is nothing. (Round to four decimal places as needed.) (b) Find the probability that a randomly selected high school student who took the reading portion of the test has a score that is between and . The probability of a student scoring between and is nothing. (Round to four decimal places as needed.) (c) Find the probability that a randomly selected high school student who took the reading portion of the test has a score that is more than . The probability of a student scoring more than is nothing. (Round to four decimal places as needed.) (d) Identify any unusual events. Explain your reasoning. Choose the correct answer below. A. than 0.05. B. than 0.05. C. The event in part is unusual because its probability is less than 0.05. D. The events in parts are unusual because its probabilities are less than 0.05.
The question is incomplete. Here is the complete question.
In a recent year, the socres for the reading portion of a test were normally distributed, with a mean of 23.3 and a standard deviation of 6.4. Complete parts (a) through (d) below.
(a) Find the probability that a randomly selected high school student who took the reading portion of the test has a score that is less than 18. (Round to 4 decimal places as needed.)
(b) Find a probability that a random selected high school student who took the reading portion of the test has a score that is between 19.9 and 26.7.
(c) Find a probability that a random selected high school student who took the reading portion of the test ahs a score that is more than 36.4.
(d) Identify any unusual events. Explain your reasoning.
Answer: (a) P(X<18) = 0.2033
(b) P(19.9<X<26.7) = 0.4505
(c) P(X>36.4) = 0.0202
(d) Unusual event: P(X>36.4)
Step-by-step explanation: First, determine the z-score by calculating:
[tex]z = \frac{x-\mu}{\sigma}[/tex]
Then, use z-score table to determine the values.
(a) x = 18
[tex]z = \frac{18-23.3}{6.4}[/tex]
z = -0.83
P(X<18) = P(z< -0.83)
P(X<18) = 0.2033
(b) x=19.9 and x=26.7
[tex]z = \frac{19.9-23.3}{6.4}[/tex]
z = -0.67
[tex]z = \frac{26.7-23.3}{6.4}[/tex]
z = 0.53
P(19.9<X<26.7) = P(z<0.53) - P(z< -0.67)
P(19.9<X<26.7) = 0.7019 - 0.2514
P(19.9<X<26.7) = 0.4505
(c) x=36.4
[tex]z = \frac{36.4-23.3}{6.4}[/tex]
z = 2.05
P(X>36.4) = P(z>2.05) = 1 - P(z<2.05)
P(X>36.4) = 1 - 0.9798
P(X>36.4) = 0.0202
(d) Events are unusual if probability is less than 5% or 0.05. So, part (c) has an unusual event.
The probability will be:
(a) 0.2038
(b) 0.4046
(c) 0.0203
(d) Event in part (c) is unusual.
According to the question,
[tex]\mu = 23.2[/tex][tex]\sigma = 6.4[/tex]Let,
"X" shows the test scores.(a)
The z-score for X=18 will be:
→ [tex]z = \frac{X- \mu}{\sigma}[/tex]
[tex]= \frac{18-23.3}{6.4}[/tex]
[tex]= -0.828[/tex]
So,
The probability will be:
→ [tex]P(X<18) = P(z < -0.828)[/tex]
[tex]= 0.2038[/tex]
(b)
The z-score for X=19.9 will be:
→ [tex]z = \frac{X -\mu}{\sigma}[/tex]
[tex]= \frac{19.9-23.3}{6.4}[/tex]
[tex]= -0.531[/tex]
The z-score for X=26.7 will be:
→ [tex]z = \frac{X -\mu}{\sigma}[/tex]
[tex]= \frac{26.7-23.3}{6.4}[/tex]
[tex]= 0.531[/tex]
So,
The probability will be:
→ [tex]P(19.9 < X< 23.3) = P(-0.531 < z< 0.531)[/tex]
[tex]= 0.4046[/tex]
(c)
The z-score for X=36.4 will be:
→ [tex]z = \frac{X -\mu}{\sigma}[/tex]
[tex]= \frac{36.4-23.3}{6.4}[/tex]
[tex]= 2.047[/tex]
So,
The probability will be:
→ [tex]P(X > 36.4 )= P(z > 2.047)[/tex]
[tex]= 0.0203[/tex]
(d)
Just because it's probability value is less than 0.05, so that the events is "part c" is unusual.
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This person did something wrong and I do not know what it is :( Please help this is for points!
Answer:
0.4 cm
Step-by-step explanation:
The magnifying glass basically zooms into smaller objects. If the insect appears to be 2cm, then it is actually smaller than this. It cannot be 10 cm.
If the scale factor is 5, then this means that the insect is zoomed in 5 times through the magnifying glass. Use the following ratio:
[tex]\frac{2}{5}[/tex]
This fraction can also be seen as division, so:
[tex]2[/tex]÷[tex]5=0.4[/tex]
The insect is actually 0.4 cm long.
(or 4 millimeters)
:Done
Match each function name with its equation.
Answer:
a. Quadratic--[tex]y=x^{2}[/tex]
b. Absolute Value--[tex]y=|x|[/tex]
c. Linear--[tex]y=x[/tex]
d. Reciprocal Squared--[tex]y=\frac{1}{x^{2} }[/tex]
e. Cubic--[tex]y=x^{3}[/tex]
f. Square Root--[tex]y=\sqrt{x}[/tex]
g. Reciprocal--[tex]y=\frac{1}{x}[/tex]
h. Cube root--[tex]y=\sqrt[3]{x}[/tex]
Answer:
Step-by-step explanation:
y=[tex]x^{2}[/tex] is quadratic
y=x is an absolute value
y= |x| os linear
y= [tex]\frac{1}{x}[/tex] is reciprocal
y= [tex]x^{3}[/tex] is cubic
y= [tex]\sqrt{x}[/tex] is square root
y= [tex]\frac{1}{x^{2} }[/tex] is reciprocal squared
y= [tex]\sqrt[3]{x}[/tex] is cube root
BRAINLIEST ANSWER GIVEN, WHY CAN'T ANYONE HELP ME?! Find the equation of the line passing through the pair points (-8,6) (-9,-9). The equation of the line in the form is Ax+By=C.
Answer:
15x - y = - 126
or y = 15x + 126
Step-by-step explanation:
will make it simple and short
to find the equation... we need to find slope first.
y2 - y1 -9 - 6
slope = m = --------- = ----------- = 15
x2 - x1 -9 - (-8)
so we know that the equation of the line using point (-8,6) and slope 15 y - 6 = 15( x + 8)
y - 6 = 15x + 120
Writing the equation in the form Ax + By = C
15x - y = -120-6
therefore.... 15x - y = - 126 or simplify it as or y = 15x + 126
Hope this helps
Please help!! find the circumference of a circle with a diameter of 13 meters
Answer:
C = 2pie(r)
r= d/2= 13/2= 6.5
C = 2*3.14*6.5
C= 41
Step-by-step explanation:
What are the solution(s) of the quadratic equation 98 - x2 = 0?
x = +27
Ox= +63
x = +7/2
no real solution
Answer:
±7 sqrt(2) = x
Step-by-step explanation:
98 - x^2 = 0
Add x^2 to each side
98 =x^2
Take the square root of each side
±sqrt(98) = sqrt(x^2)
±sqrt(49*2) = x
±7 sqrt(2) = x
Answer:
[tex]\huge \boxed{{x = \pm 7\sqrt{2} }}[/tex]
Step-by-step explanation:
[tex]98-x^2 =0[/tex]
[tex]\sf Add \ x^2 \ to \ both \ sides.[/tex]
[tex]98=x^2[/tex]
[tex]\sf Take \ the \ square \ root \ of \ both \ sides.[/tex]
[tex]\pm \sqrt{98} =x[/tex]
[tex]\sf Simplify \ radical.[/tex]
[tex]\pm \sqrt{49} \sqrt{2} =x[/tex]
[tex]\pm 7\sqrt{2} =x[/tex]
[tex]\sf Switch \ sides.[/tex]
[tex]x= \pm 7\sqrt{2}[/tex]
if the LCM and the HCF of two numbers are 9 and 3, respectively, what are the numbers?
Hey There!
Answer:
HCF = 9 (With the two numbers) - 18,9LCM = 3 (with the two numbers) - 6,9Step-by-step explanation:
HCF
If HCF is ''9'' that means that ''9'' is the divisible of two numbers.
So 18 and 19 can be divided by 9 and that's the highest divisible for both factors.
And always remeber the answer is a ''Prime factor.''
LCM
If LCM is ''3'' that means ''3'' is the lowest common multiple out of two numbers.
Hope this helps!
Have a nice Day!:)
On a particular production line, the likelihood that a light bulb is defective is 10%. seven light bulbs are randomly selected. What is the probability that at most 4 of the light bulbs will be defective
Answer:
0.9995
Step-by-step explanation:
10% = 0.10
1 - 0.10 = 0.9
n = number of light bulbs = 7
we calculate this using binomial distribution.
p(x) = nCx × p^x(1-p)^n-x
our question says at most 4 is defective
= (7C0 × 0.1⁰ × 0.9⁷) + (7C1 × 0.1¹ × 0.9⁶) + (7C2 × 0.1² × 0.9⁵) + (7C3 × 0.1³ × 0.9⁴) + (7C4 × 0.1⁴ × 0.9³)
= 0.478 + 0.372 + 0.1239 + 0.023 + 0.0026
= 0.9995
we have 0.9995 probability that at most 4 light bulbs are defective.
I need help please help meee I don’t understand
Answer:
204
Step-by-step explanation:
To simplify the shape, you can do multiple things. I've opted to shave down both prongs to take it from a 'T' shape to a rectangular prism.
For height of the prongs, take 4 from 6.
6 - 4 = 2
Divide by 2 as there are 2 prongs.
2 / 2 = 1
Remember L * W * H
6 * 3 * 1 = 18
Remember that there are two prongs!
3 + 4 = 7
6 * 7 * 4 = 168
168 + 2(18) = 204
If your starting salary is $40000 and you receive a 3% increase at the end of every year, what is the total amount, in dollars, you will earn one the first 16 years that you work
Answer:
Total amount in dollars= $64614.00
Step-by-step explanation:
Initial starting salary is $40000.
Rate of increase is 3%
Number of years is 16 years
The salary is compounded yearly.
Amount A after 16 years is given as
A= p (1+r/n)^ (nt)
A=40000(1+0.03/16)^(16*16)
A= 40000(1.001875)^(256)
A=40000(1.61534824)
A= 64613.92959
Total amount in dollars= $64614.00
Answer: the answer is $806275
Step-by-step explanation:
A p e x
What is the solution of the system of equations?
y = -3x + 7
y = 2x - 8
Answer:
x = 3, y = -2
Step-by-step explanation:
Since y=y
then, -3x +7 = 2x-8
7+8 = 3x+2x
15 = 5x
x=3
substitute
y = 2(3) - 8
y = -2
Hope that helped!!! k
Answer:
y = -2
x = 3
Step-by-step explanation:
Solve using elimination
1. Rearrange the equations to make it easier to solve
y = -3x + 7 → 3x + y = 7
y = 2x - 8 → 2x - y = 8
2. Multiply the equations to have a matching coefficient
2(3x + y = 7) = 6x + 2y = 14
3(2x - y = 8) = 6x - 3y = 24
3. Subtract
6x + 2y = 14
- 6x - 3y = 24
0 + 5y = -10
4. Solve for y
5y = -10
y = -2
5. Substitute y in any equation to solve for x
-2 = -3x + 7
-3x = -9
x = 3
Please helppp meee I don’t know the answer
Answer:
First use the protractor then round the number to the nearest 10
Answer:
Round to the nearest tenth
Step-by-step explanation:
A. Suppose two dice (one red, one green) are rolled. Consider the following events. A: the red die shows 1; B: the numbers add to 4; C: at least one of the numbers is 1; and D: the numbers do not add to 10. Express the given event in symbols.
The red die shows 1 and the numbers add to 4.
How many elements does it contain?
B. Suppose two dice (one red, one green) are rolled. Consider the following events. A: the red die shows 3; B: the numbers add to 2; C: at least one of the numbers is 1; and D: the numbers do not add to 10. Express the given event in symbols. HINT [See Example 5.]
The numbers do not add to 2.
How many elements does it contain?
C. Suppose two dice (one red, one green) are rolled. Consider the following events. A: the red die shows 1; B: the numbers add to 2; C: at least one of the numbers is 3; and D: the numbers do not add to 11. Express the given event in symbols. HINT [See Example 5.]
Either the numbers add to 11 or the red die shows a 1.
How many elements does it contain?
D. Suppose two dice (one red, one green) are rolled. Consider the following events. A: the red die shows 4; B: the numbers add to 5; C: at least one of the numbers is 1; and D: the numbers do not add to 9. Express the given event in symbols. HINT [See Example 5.]
Either the numbers add to 5, or they add to 9, or at least one of them is 1.
How many elements does it contain?
Answer:
1. elements it contains = (1,3)
2. elements it contains = 35
3. elements it contains = 8
4. elements it contains = 17
Step-by-step explanation:
A. Suppose two dice (one red, one green) are rolled. Consider the following events. A: the red die shows 1; B: the numbers add to 4; C: at least one of the numbers is 1; and D: the numbers do not add to 10. Express the given event in symbols.
The red die shows 1 and the numbers add to 4.
How many elements does it contain?
B. Suppose two dice (one red, one green) are rolled. Consider the following events. A: the red die shows 3; B: the numbers add to 2; C: at least one of the numbers is 1; and D: the numbers do not add to 10. Express the given event in symbols. HINT [See Example 5.]
The numbers do not add to 2.
How many elements does it contain?
C. Suppose two dice (one red, one green) are rolled. Consider the following events. A: the red die shows 1; B: the numbers add to 2; C: at least one of the numbers is 3; and D: the numbers do not add to 11. Express the given event in symbols. HINT [See Example 5.]
Either the numbers add to 11 or the red die shows a 1.
How many elements does it contain?
D. Suppose two dice (one red, one green) are rolled. Consider the following events. A: the red die shows 4; B: the numbers add to 5; C: at least one of the numbers is 1; and D: the numbers do not add to 9. Express the given event in symbols. HINT [See Example 5.]
Either the numbers add to 5, or they add to 9, or at least one of them is 1.
How many elements does it contain?
NB. Attached is the solution to the problems stated above
Find the side length, b.
Round to the nearest tenth.
Answer:
b ≈ 9.2
Step-by-step explanation:
Using Pythagoras' identity in the right triangle.
The square on the hypotenuse is equal to the sum of the squares on the other 2 sides, that is
b² = a² + c² = 6² +7² = 36 + 49 = 85 ( take the square root of both sides )
b = [tex]\sqrt{85}[/tex] ≈ 9.2 ( to the nearest tenth )
Answer:
9.22
Step-by-step explanation:
Since it's a 90° triangle [tex]c^{2} =a^{2} +b^{2}[/tex].
In this example they labeled the hypotenuse as b instead of c are equation is still the same just put the correct variables in the right places.
[tex]b = \sqrt{6^{2} +7^{2} }[/tex]
b = 9.22
The joint density function for a pair of random variables X and Y is given. f(x, y) = Cx(1 + y) if 0 ≤ x ≤ 4, 0 ≤ y ≤ 4 0 otherwise f(x,y) = 0
A) Find the value of the constant C. I already have 1/24.
B) Find P(X < = 1, Y < = 1)
C) Find P(X + Y < = 1).
Answer:
A) C = 1/96
B) P(x<=1, y<=1) = 1/128 or 0.0078125 to 7 places
C) P(x+y<=1) = 5/2305, or 0.0021701 to 7 places
Step-by-step explanation:
f(x,y) = C x (1+y)
A)
To find C, we need to integrate the volume under region bound by
0 <= x <= 4, and
0 <= y <= 4
This volume equals 1.0.
Find integral,
int( int(f(x,y),x=0,4), y = 0,4) = 96C
therefore C = 1/96
or
F(x,y) = x (1+y) / 96 ............................(1)
B)
P(x<=1, y<=1)
Repeat the integral, substitute the appropriate limits,
P = int( int(F(x,y),x=0,1), y = 0,1)
= 1/128 or 0.0078125
P(x<=1, y<=1) = 1/128 or 0.0078125 to 7 places
C)
P(x+y<=1)
From the function, we know that this is going to be less than one half of the probability in (B), closer to 1/4 of the previous.
It will be again a double integral, as follows:
P = int( int(F(x,y),x=0,1-y), y = 0,1)
= 5/2304
= 0.0021701 (to 7 decimals)
P(x+y<=1) = 5/2305, or 0.0021701 to 7 places
pls help :Find the missing side or angle.
Round to the nearest tenth.
Answer:
C° = 71.6056
Step-by-step explanation:
Law of Cosines: c² = a² + b² - 2abcosC°
Step 1: Plug in known variables
29² = 30² + 15² - 2(30)(15)cosC°
Step 2: Evaluate
841 = 900 + 225 - 900cosC°
-59 = 225 - 900cosC°
-284 = -900cosC°
71/225 = cosC°
cos⁻¹(71/225) = C°
C° = 71.6056
And we have our answer!
Answer:
79.0°
Step-by-step explanation:
The Law of Cosines is used for this purpose. It tells you ...
a² = b² +c² -2bc·cos(A)
Solving for A gives ...
cos(A) = (b² +c² -a²)/(2bc) = (15² +29²-30²)/(2(15)(29)) = 166/870
Using the inverse cosine function, we find the angle to be ...
A = arccos(166/870) ≈ 79.00026°
A ≈ 79.0°
Multiple-Choice Questions
1. In 1995, Diana read 10 English books and 7 French books. In 1996, she read twice as many French books as English books. If 60% of the books that she read during the 2 years were French, how many English and French books did she read in 1996?
(A) 16
(B) 26
(0) 32
(D) 48
Answer:
(D) 48
Step-by-step explanation:
Let English book = x
Let french book = y
In 1995 x= 10
Y= 7
In 1996
Y = 2x
Total book read in the two years
0.6(Total) = y
0.4(total) = x
We don't know the exact amount of books read in 1996.
Total = 10 + 7 +x +2x
Total = 17+3x
0.6(total) = 7+2x
0.6(17+3x) = 7+2x
10.2 +1.8x= 7+2x
10.2-7= 2x-1.8x
3.2= 0.2x
3.2/0.2= x
16= x
So she read 16 English book
And 16*2 = 32 french book Making it a total of 16+32= 48 books in 1996
Describe each of the following values as (A) a discrete random variable, (B) a continuous random variable, or (C) not a random variable:
1. Exact weight of quarters now in circulation in the United States
2. Shoe sizes of humans
3. Political party affiliations of adults in the United States
A. 1.C
2.A
3.В
B. 1.B
2.A
3.С
C. 1.A
2.C
3.В
D. 1.A
2.В
3.С
Answer:
(1) B
(2) A
(3) C
Step-by-step explanation:
A random variable is a variable that denotes a set of all the possible outcomes of a random experiment. It is denotes by a single capital letter such as X or Y.
There are two types of random variables.
Discrete random variable: These type of random variable takes finite number of values, such as 0, 1, 2, 3, 4, ... For example, number of girl child in a neighborhood.Continuous random variable: These type of random variables takes infinite number of possible values. For example, the height, weight.(1)
Exact weight of quarters now in circulation in the United States.
The variable weight is a continuous variable.
Thus, the exact weight of quarters now in circulation in the United States is a continuous random variable.
(2)
Shoe sizes of humans.
The shoe size of a person are discrete and finite values.
Thus, the shoe sizes of humans are discrete random variables.
(3)
Political party affiliations of adults in the United States.
This variable is not a quantitative variable.
It is a qualitative variable.
Thus, the political party affiliations of adults in the United States is no random variable.
4 solid cubes were made out of the same material. All four have different side lengths: 6cm, 8cm, 10cm, and 12cm. How to distribute the cubes onto two plates of a scale so the scale is balanced? Answer: A= the cube with side length 6 cm, B= the cube with side length 8 cm, C= the cube with side length 10 cm, D= the cube with side length 12 cm. On one side of the scale : , on the other side of the scale
Answer: The cube with side length of 12cm is alone in one plate, the other 3 cubes are in the other plate.
Step-by-step explanation:
We have 4 cubes with side lengths of:
6cm, 8cm, 10cm and 12cm.
Now, some things you need to know:
If we want a scale to be balanced, then the mass in both plates must be the same.
The volume of a cube of side length L is:
V = L^3
And the mass of an object of density D, and volume V is:
M = D*V.
As all the cubes are of the same material, all of them have the same density, so the fact that we do not know the value of D actually does not matter here.
Then we want to forms two groups of cubes in such a way that the total volume in each plate is the same (or about the same), the volumes of the cubes are:
Cube of 6cm:
V = (6cm)^3 = 216cm^3
Cube of 8cm:
V = (8cm)^3 = 512cm^3
Cube of 10cm:
V = (10cm)^3 = 1000cm^3
cube of 12cm
V = (12cm)^3 = 1728cm^3
First, if we add the volumes of the first two cubes, we have:
V1 = 216cm^3 + 512cm^3 = 728cm^3
Now we can see that we add 1000cm^3 the volume will be equal to the volume of the larger cube, so here we can also add the cube with side length of 10cm
Then the volume of the 3 smaller cubes together is:
V1 = 216cm^3 + 512cm^3 + 1000cm^3 = 1728cm^3.
Then, if we want to have the same volume in each plate, then we need to have the 3 smaller cubes in one plate, and the larger cube in the other plate.
An arithmetic sequence has this recursive formula: (a^1 =8, a^n= a^n-1 -6
A.a^n=8+(n-6)(-1)
B.a^n=8+(n-1)(-6)
C.
Answer:
[tex]a_n = 8 + (n - 1) (-6)[/tex]
Step-by-step explanation:
Given
[tex]a_1 = 8[/tex]
Recursive: [tex]a_{n} = a_{n-1} - 6[/tex]
Required
Determine the formula
Substitute 2 for n to determine [tex]a_2[/tex]
[tex]a_{2} = a_{2-1} - 6[/tex]
[tex]a_{2} = a_{1} - 6[/tex]
Substitute [tex]a_1 = 8[/tex]
[tex]a_2 = 8 - 6[/tex]
[tex]a_2 = 2[/tex]
Next is to determine the common difference, d;
[tex]d = a_2 - a_1[/tex]
[tex]d = 2 - 8[/tex]
[tex]d = -6[/tex]
The nth term of an arithmetic sequence is calculated as
[tex]a_n = a_1 + (n - 1)d[/tex]
Substitute [tex]a_1 = 8[/tex] and [tex]d = -6[/tex]
[tex]a_n = a_1 + (n - 1)d[/tex]
[tex]a_n = 8 + (n - 1) (-6)[/tex]
Hence, the nth term of the sequence can be calculated using[tex]a_n = 8 + (n - 1) (-6)[/tex]
Techwiz electronics makes a profit of $35 for each mp3 and $18 for each DVD last week techwiz sold a combined total of 118 mp3 and DVD players. Let x be the number of mp3 sold last week write an expression for the combined total profit (in dollars) made last week
Answer:
The total profit is [tex]p = 17x + 2124[/tex]
Step-by-step explanation:
From the question we are told that
The profit made on each mp3 is k = $35
The profit made on each mp3 is y = $18
The total amount sold is n = 118
Now given that the amount of mp3 sold is x then the amount of DVD sold is mathematically evaluated as
[tex]n - x[/tex]
Now the profit made on the x number of mp3 sold is
[tex]x * 35 = 3x[/tex]
And the the profit made from the n-x number of DVD sold is 18 (n-x ) = 18 - 18x
So the total profit made last week from the sales of both mp3 and DVD is
[tex]p = 35x + 18n - 18x[/tex]
[tex]p = 17x + 18(118)[/tex]
[tex]p = 17x + 2124[/tex]
