Complete Question
Assume that random guesses are made for 7 multiple-choice questions on a test with 5 choices for each question, so that there are n=7 trials, each with probability of success (correct) given by p=0.20. Find the probability of no correct answers.
Answer:
The probability is [tex]P(X = 0 ) = 0.210[/tex]
Step-by-step explanation:
From the question we are told that
The number of trial is n = 7
The probability of success is p = 0.20
Generally the probability of failure is
[tex]q = 1- 0.20[/tex]
[tex]q = 0.80[/tex]
Given that this choices follow a binomial distribution as there is only two probabilities i.e success or failure
Then the probability is mathematically represented as
[tex]P(X = 0 ) = \left n} \atop {}} \right. C_0 * p^{0} * q^{n- 0}[/tex]
[tex]P(X = 0 ) = \left 7} \atop {}} \right. C_0 * (0.2)^{0} * (0.8)^{7- 0}[/tex]
Here [tex]\left 7} \atop {}} \right. C_0 = 1[/tex]
=> [tex]P(X = 0 ) = 1 * 1* (0.8)^{7- 0}[/tex]
=> [tex]P(X = 0 ) = 0.210[/tex]
A jar contains 8 pennies, 5 nickels and 7 dimes. A child selects 2 coins at random without replacement from the jar. Let X represent the amount in cents of the selected coins. Be very precise with your answers.
a. Find the probability x = 2 cents.
b. Find the probability x = 6 cents.
c. Find the probability x = 10 cents.
d. Find the probability x = 11 cents.
e. Find the probability x = 15 cents.
f. Find the probability x = 20 cents.
g. Find the expected value of x.
Answer:
a. The probability x = 2 cents = 7/22
b. The probability x = 6 cents = 35/66
c. The probability x = 10 cents = 5/33
d. The probability x = 11 cents= 28/33
e. The probability x = 15 cents = 20/33
f. The probability x = 20 cents = 14/33
g. The expected value of x = 5.9
Step-by-step explanation:
This is a binomial probability distribution. The number of trials is known .
a. The probability x = 2 cents.
Probability ( X=2) P( selecting 2 dimes)= 7C2 / 12c2
= 21 / 66 = 7/22
b. The probability x = 6 cents.
Probability ( X=6) P( selecting a nickel and a dime)= 5C1 * 7C1/ 12c2
= 5*7 / 66 = 35/66
c. The probability x = 10 cents.
Probability ( X=10) P( selecting two nickels )= 5C2 / 12c2)
= 10/ 66 = 5/33
d. The probability x = 11 cents.
Probability ( X=11) P( selecting a penny and a dime)= 8C1 * 7C1/ 12c2)
= 8*7 / 66 = 56/66= 28/33
e. The probability x = 15 cents.
Probability ( X=15) P( selecting a penny and a nickel)= 8C1 * 5C1/ 12c2)
= 8*5 / 66 = 40/66= 20/33
f. The probability x = 20 cents.
Probability ( X=20) P( selecting 2 pennies )= 8C2 / 12c2)
= 28 / 66 = 14/33
g. The expected value of x.
E(X) = np
E(X) = 2 * (8C2+ 5C2+ 7C2)/(8+5+7) = 2( 28+10+21)/20
=2(59)/20= 5.9
Answer two questions about Equations A and B: A.5x=20 \ B.x=4 1) How can we get Equation B from Equation A? Choose 1 answer: (Choice A) Multiply/divide both sides by the same non-zero constant (Choice B,) Multiply/divide both sides by the same variable expression (Choice C) Add/subtract the same quantity to/from both sides (Choice D) Add/subtract a quantity to/from only one side
Answer:
Multiply/divide both sides by the same non-zero constant
Step-by-step explanation:
5x = 20
Divide each side by 5
5x/5 = 20/5
x = 4
To obtain (B) from (A) "Multiply/divide both sides by the same non-zero constant"
Given the equations :
5x = 20 ___ (A)x = 4 _____ (B)To obtain the value ; x = 4 from A
We multiply (A) by the same non-zero constantHere, the constant value which can be used is 5 in other to isolate 'x'
5x/5 = 20/5
x = 4
Therefore, to obtain (B) from (A) "Multiply/divide both sides by the same non-zero constant"
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Bob cycles 5.4 km every morning.how many feet are in 5.4 km, given that 1 mile=1.609 km and 1 mile=5,280 feet?
Answer:
17,720 ft
Step-by-step explanation:
5.4 km * (1 mile)/(1.609 km) * (5280 ft)/(1 mile) = 17,720 ft
Determine whether the sequence converges or diverges. If it converges, find the limit. (If an answer does not exist, enter DNE.)
an = (−3^n)/(4n!)
Answer:
[tex]a_{i} = \frac{(-3)^{i}}{4\cdot i!}[/tex] converges.
Step-by-step explanation:
The convergence analysis of this sequence is done by Ratio Test. That is to say:
[tex]r = \frac{a_{n+1}}{a_{n}}[/tex], where sequence converges if and only if [tex]|r| < 1[/tex].
Let be [tex]a_{i} = \frac{(-3)^{i}}{4\cdot i!}[/tex], the ratio for the expression is:
[tex]r =-\frac{3}{n+1}[/tex]
[tex]|r| = \frac{3}{n+1}[/tex]
Inasmuch [tex]n[/tex] becomes bigger, then [tex]r \longrightarrow 0[/tex]. Hence, [tex]a_{i} = \frac{(-3)^{i}}{4\cdot i!}[/tex] converges.
A particular country has total states. If the areas states are added and the sum is divided by , the result is square kilometers. Determine whether this result is a statistic or a parameter.
Answer:
Some texts are missing from the question, I found a possible match, and here it is:
A particular country has total of 45 states. If the areas of 35 states are added and the sum is divided by 35, the result is 135,600 square kilometres. Determine whether this result is a statistic or a parameter.
Answer:
The result is a statistic because the data involved are samples.
Step-by-step explanation:
A Parameter is a numerical representation of an entire population. That is they are numbers summarizing data for an entire population. In this case, if all the 45 states were measured, the result would have been a parameter.
On the other hand, statistics are numbers that are subsets (representative portions) of an entire population. Since 35 states were chosen out of 45 states, the average area of the 35 states is a statistic and not a parameter.
An urn contains 9 red marbles, 6 white marbles, and 8 blue marbles marbles. A child randomly selects three (without replacement) from the urn. Find the probability all three marbles are the same color
Answer:
P(identical colours) = 160/1771 (0.0903 to four decimals)
Step-by-step explanation:
Given 9R, 6W and 8B marbles (total = 9+6+8 = 23)
Choose three without replacement.
Need probability three identical colours.
Use the multiplication rule.
P(RRR) = 9/23 * 8*22 * 7*21 = 12 / 253
P(WWW) = 6/23 * 5/22 * 4/21 = 20/1771
P(BBB) = 8/23 * 7/22 * 6/21 = 8/153
Probability of getting identical colours
= P(RRR)+P(WWW)+P(BBB)
= 160/1771 (0.0903 to four decimals)
Using the probability concept, it is found that there is a 0.0903 = 9.03% probability all three marbles are the same color.
-----------------
A probability is the number of desired outcomes divided by the number of total outcomes.The order in which the marbles are chosen is not important, and they are also chosen without replacement, which means that the combination formula is used to find the number of outcomes.-----------------
Combination formula:
[tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
-----------------
The desired outcomes can be:
3 from a set of 9(all red).3 from a set of 6(all white).3 from a set of 8(all blue).Thus:
[tex]D = C_{9,3} + C_{6,3} + C_{8,3} = \frac{9!}{3!6!} + \frac{6!}{3!3!} + \frac{8!}{3!5!} = 160[/tex]
-----------------
The total outcomes are 3 from a set of 9 + 6 + 8 = 23. Thus:
[tex]T = C_{23,3} = \frac{23!}{3!20!} = 1771[/tex]
The probability is:
[tex]p = \frac{D}{T} = \frac{160}{1771} = 0.0903[/tex]
0.0903 = 9.03% probability all three marbles are the same color.
A similar problem is given at https://brainly.com/question/10896842
The image of (-4,6) reflected along the y-axis is
a. (4, -6)
b. (-4,-6)
c. (4, 6)
d. (-4, 6)
Answer:
C(4,6)
Step-by-step explanation:
the x turns into its opposite when reflected across y same thing for y when reflected across x
Answer:
c. (4, 6)
Step-by-step explanation:
The rule of an reflection about the y-axis is: [tex]A(x,y)\rightarrow A'(-x,y)[/tex]
Apply the rule to point (-4, 6):
[tex]\frac{(-4,6)\rightarrow\boxed{(4,6)}}{(x,y)\rightarrow(-x,y)}[/tex]
Option C should be the correct answer.
If there are 25 students in a class - 11 are guys and 14 are girls what is the probability that one of the students on the class is a guy?
Answer:
0.44
Step-by-step explanation:
11/25 = 0.44 = 44%
Answer:
11/25
Step-by-step explanation:
since there are 25 students, there will be 25 choices, and the 25 will be the denominator
and there are 11 guys so there will be 11 choices of guys and the 11 will go on top
In order to study the mean blood pressure of people in his town, Richard samples the population by dividing the residents by age and randomly selecting a proportionate number of residents from each age group. Which type of sampling is used?
a. Convenience sampling
b. Cluster sampling
c. Stratified sampling
d. Systematic sampling
Answer:
C Stratified sampling
Step-by-step explanation:
Stratified sampling : Stratified sampling is a type of sampling technique in which the total population is divided into smaller groups or strata to complete the sampling process. The strata is formed based on some common characteristics in the data of the population.
One of the advantage of stratified random sampling is that it covers important population characteristics in the sample.
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Answer:
32.8 miles
Step-by-step explanation:
Amy is driving to Seattle. Suppose that the remaining distance to drive (in miles) is a linear function of her driving time (in minutes). When graphed, the function gives a line with a slope of -0.95. See the figure below. Amy has 48 miles remaining after 31 minutes of driving. How many miles will be remaining after 47 minutes of driving?
Answer: The general equation of a line is given as y = mx + c, where m is the slope of the line and c is the intercept on the y axis. Given that the slope is -0.95, substituting in the general equation :
y = -0.95x + c
Amy has 48 miles remaining after 31 minutes of driving, to find c, we substitute y = 48 and x = 31. Therefore:
48 = -0.95(31) + c
c = 48 + 0.95(31)
c = 48 + 29.45
c = 77.45
The equation of the line is
y = -0.95x + 77.45
After 47 minutes of driving, the miles remaining can be gotten by substituting x = 47 and finding y.
y = -0.95(47) + 77.45
y = -44.65 + 77.45
y = 32.8 miles
2. Imagine you are one of the people who left the luncheon with a contagious disease and interacted with an average of 9 different people each day. How many people could potentially be infected in 7 days
Answer:
63 people.
Step-by-step explanation:
If you have a contagious disease and met with 9 different people each day for 7 days, that'll be 63 people that have gotten infected. 9 x 7 = 63. Hope this helps you!
How many solutions does the following equation have ?
−3x+9−2x=−12−5x
[tex]\text{Solve for x:}\\\\-3x+9-2x=-12-5x\\\\\text{Combine like terms}\\\\-5x+9=-12-5x\\\\\text{Add 5x to both sides}\\\\9=-12\\\\\text{Since that's not valid, there would be no solutions}\\\\\boxed{\text{No solutions}}[/tex]
What is the minimum sample size required to estimate a population mean with 90% confidence when the desired margin of error is 1.25
Complete Question
What is the minimum sample size required to estimate a population mean with 90% confidence when the desired margin of error is 1.25? The standard deviation in a pre-selected sample is 7.5
Answer:
The minimum sample size is [tex]n =97[/tex]
Step-by-step explanation:
From the question we are told that
The margin of error is [tex]E = 1.25[/tex]
The standard deviation is [tex]s = 7.5[/tex]
Given that the confidence level is 90% then the level of significance is mathematically represented 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 minimum sample size is mathematically evaluated as
[tex]n = \frac{Z_{\frac{\alpha }{2} * s^2 }}{E^2 }[/tex]
=> [tex]n = \frac{1.645^2 * 7.5^2 }{1.25^2 }[/tex]
=> [tex]n =97[/tex]
Find 0.01 more than 9.154
Answer:
Hey!
Your answer is 9.164!!
Step-by-step explanation:
Adding 0.01 means just adding 1 to THE DIGIT IN THE HUNDRETH PLACE...2 SPACES RIGHT OF DECIMAL POINT!
5+1=6
SUB IN:
9.164
In this diagram, bac~edf. if the area of bac= 6 in.², what is the area of edf? PLZ HELP PLZ PLZ PLZ PLZ
Answer:
Area of ΔEDF = 2.7 in²
Step-by-step explanation:
It's given in the question,
ΔBAC ~ ΔEDF
In these similar triangles,
Scale factor of the sides = [tex]\frac{\text{Measure of one side of triangle BAC}}{\text{Measure of one side of triangle EDF}}[/tex]
[tex]=\frac{\text{BC}}{\text{EF}}[/tex]
[tex]=\frac{3}{2}[/tex]
Area scale factor = (Scale factor of the sides)²
[tex]\frac{\text{Area of triangle BAC}}{\text{Area of triangle EDF}}=(\frac{3}{2})^2[/tex]
[tex]\frac{6}{\text{Area of triangle EDF}}=(\frac{9}{4})[/tex]
Area of ΔEDF = [tex]\frac{6\times 4}{9}[/tex]
= 2.67
≈ 2.7 in²
Therefore, area of the ΔEDF is 2.7 in²
Rational equation of 3/x+1=2/x-3
Answer:
x = 11
Step-by-step explanation:
3/x+1=2/x-3
Solve by using cross products
2 (x+1) = 3 (x-3)
Distribute
2x+2 = 3x-9
Subtract 2x
2x+2-2x = 3x-2x-9
2 = x-9
Add 9 to each side
2+9 =x-9+9
11 =c
Was is a macroeconomics
Answer:
Macroeconomics is a study that deals with the whole economy and everything pertaining to it.
Step-by-step explanation:
when we talk about Macroeconomics, we mean the whole economy. It can be related to a country's import or export, governance, how resources are accurately allocated to people in the country and the like.
In a random sample of 64 people, 48 are classified as 'successful.' Determine the sample proportion of 'successful' people.
Answer:
The sample proportion of 'successful' people is [tex]\frac{3}{4}[/tex].
Step-by-step explanation:
The sample consist of 64 people and 48 of them are 'successful'. Hence, the proportion of 'successful' people is:
[tex]p = \frac{n}{N}[/tex]
Where:
[tex]N[/tex] - People that forms the sample, dimensionless.
[tex]n[/tex] - People classified as 'successful', dimensionless.
Given that [tex]n = 48[/tex] and [tex]N = 64[/tex], the sample proportion of 'successful' people is:
[tex]p = \frac{48}{64}[/tex]
[tex]p = \frac{3}{4}[/tex]
The sample proportion of 'successful' people is [tex]\frac{3}{4}[/tex].
The average value of a function f(x, y, z) over a solid region E is defined to be fave = 1 V(E) E f(x, y, z) dV where V(E) is the volume of E. For instance, if rho is a density function, then rhoave is the average density of E. Find the average value of the function f(x, y, z) = 5x2z + 5y2z over the region enclosed by the paraboloid z = 9 − x2 − y2 and the plane z = 0.
Answer:
An aluminum bar 4 feet long weighs 24 pounds
Step-by-step explanation:
Pablo rented a truck for one day. There was a base fee of $19.99, and there was an additional charge of 80 cents for each mile driven. Pablo had to pay
$221.59 when he returned the truck. For how many miles did he drive the truck?
Answer:
252 miles
Step-by-step explanation:
19.99 + .80x = 221.59
,80x = 201.60
x = 252
(II) Time intervals measured with a stopwatch typically have an uncertainty of about 0.2 s, due to human reaction time at the start and stop moments.What is the percent uncertainty of a hand-timed measurement of (a) 5.5 s, (b) 55 s, (c) 5.5 min?
Answer:
(a) 36.36%
(b) 0.36%
(c) 0.06%
Step-by-step explanation:
Given that the time intervals measured with a stopwatch have an uncertainty of about 0.2 s.
We want to know what is the percent uncertainty of a hand-timed measurement of:
(a) 5.5 s
Percentage = (0.2/5.5) × 100
≈ 36.36%
(b) 55 s
Percentage = (0.2/55)×100
≈ 0.36%
(c) 5.5 min
5.5 min = 5.5 × 60 s
= 330 s
Percentage = (0.2/330)×100
≈ 0.06%
A taste test asks people from Texas and California which pasta they prefer, brand A or brand B. The table shows the results. A person is randomly selected from those tested. What is the probability that the person is from Texas, given that the person prefers Brand B? PLEASE HELP! I'll name you Brainliest if you're answer is the best!
Answer:
A
Step-by-step explanation:
It would be A because there are 45 people in Texas that prefer brand B. There are 105 people in total that prefer brand B. 45/105 is .42857... so rounded it would be .43, therefore A. I hope this helps.
Answer:
A
Step-by-step explanation:
Which graph has an amplitude of 1/2?
Answer:
Step-by-step explanation:
The only graph shown in the question doesn't have amplitude 1/2. look for a graph of a periodic wave function that has maximum y-value 1/2 (0.5) and minimum y-value 1/2 (0.5), or if it is not oscillating around the x-axis, verifies that the distance between minimum y-value and maximum y-value is "1" (one). This is because the amplitude is half of the peak-to-peak distance.
Look at the attached image as example.
Answer:
Answer is B
Step-by-step explanation:
Did it on Edge
Whats 18x^3 divided by 7x?????
Solve the following equation algebraically:
3x^2=12
a.+3
b. +2
C.+3.5
d. +1.5
Answer:
Step-by-step explanation:
answer is c just took test
determine if the following side lengths create an acute,obtuse,or right triangle. a) 20, 21, 28 b) 3, 6, 4 c) 8, 12, 15
Answer:
a) 20, 21, 28 : acute
b) 3, 6, 4 : obtuse
c) 8, 12, 15 : obtuse
Step-by-step explanation:
You can see if a triangle is acute, obtuse, or right using the Pythagorean theorem as follows:
If [tex]a^2+b^2=c^2[/tex] , then the triangle is right.
If [tex]a^2+b^2>c^2[/tex] , then the triangle is acute.
If [tex]a^2+b^2<c^2[/tex] , then the triangle is obtuse.
Solve each to find if the given lengths form an acute, obtuse, or right triangle ( The biggest number is the hypotenuse length, since the hypotenuse is always the longest side in a triangle. This is represented by c):
a) 20, 21, 28
Insert numbers, using 28 as c:
[tex]20^2+21^2[/tex]_[tex]28^2[/tex]
Simplify exponents ([tex]x^2=x*x[/tex]):
[tex]400+441[/tex]_[tex]784[/tex]
Simplify addition:
[tex]841[/tex]_[tex]784[/tex]
Identify relationship:
[tex]841>784[/tex]
The sum of the squares of a and b is greater than the square of c. This triangle is acute.
b) 3, 6, 4
Insert numbers, using 6 as c:
[tex]3^2+4^2[/tex]_[tex]6^2[/tex]
Simplify exponents:
[tex]9+16[/tex]_[tex]36[/tex]
Simplify addition:
[tex]25[/tex]_[tex]36[/tex]
Identify relationship:
[tex]25<36[/tex]
The sum of the squares of a and b is less than the square of c. This triangle is obtuse.
c) 8, 12, 15
Insert numbers, using 15 as c:
[tex]8^2+12^2[/tex]_[tex]15^2[/tex]
Simplify exponents:
[tex]64+144[/tex]_[tex]225[/tex]
Simplify addition:
[tex]208[/tex]_[tex]225[/tex]
Identify relationship:
[tex]208<225[/tex]
The sum of the squares of a and b is less than the square of c. This triangle is obtuse.
:Done.
The correct values are,
a) 20, 21, 28 = Acute
b) 3, 6, 4 = Obtuse
c) 8, 12, 15 = Obtuse
What is mean by Triangle?A triangle is a three sided polygon, which has three vertices and three angles which has the sum 180 degrees.
Given that;
The sides are,
a) 20, 21, 28
b) 3, 6, 4
c) 8, 12, 15
Now,
We know that;
If three sides of a triangle are a, b and c.
Then, We get;
If a² + b² = c², then the triangle is right triangle.
If a² + b² > c², then the triangle is acute triangle.
If a² + b² < c², then the triangle is obtuse triangle.
Here, For option a;
⇒ 20, 21, 28
Clearly, a² + b² = 20² + 21²
= 400 + 441
= 841
And, c² = 28² = 784
Thus, a² + b² > c²
Hence, It shows the acute angle.
For option b;
⇒ 3, 6, 4
Clearly, a² + b² = 3² + 4²
= 9 + 16
= 25
And, c² = 6² = 36
Thus, a² + b² < c²
Hence, It shows the obtuse angle.
For option c;
⇒ 8, 12, 15
Clearly, a² + b² = 8² + 12²
= 64 + 144
= 208
And, c² = 15² = 225
Thus, a² + b² < c²
Hence, It shows the obtuse angle.
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For a given confidence level, t ? df is larger than z ? . Explain how t ∗ df being slightly larger than z ∗ affects the width of the confidence interval.
Answer:
Answer is below
Step-by-step explanation:
The width of the CI is directly proportional to critical value. When t* is greater than z value, the t value would then cause the margin of error to be larger and this will in turn cause the width of the confidence interval to be larger.
Greater t*df than z* gives us a bigger margin of error. This would in turn give bigger width of confidence interval. t distribution has greater width confidence interval compared to z distribution.
The width of confidence interval is a function of the margin of error. If the critical value of t(t*) is slightly larger than the critical value of z(z*), then the width of the confidence interval will be larger.
The margin of error is the product of the critical value and the standard error. Therefore, given the same standard error value, the value of the margin of error will increases based on the value of the critical value.
Since, t* is slightly larger than z*, then the confidence interval, t will be wider.
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The length of a rectangle is twice its width. If the perimeter of the rectangle is 30m, find its area.
Answer:
If the perimeter of the rectangle is 30cm , find its area. W=5 FOR THE WIDTH. 5*10=50 FOR THE AREA.
Step-by-step explanation:
The area of the Rectangle is 50 sq.m
What is the formula of Area of Rectangle?The area of rectangle for a rectangle of length L and width W is given by
A = L* W
It is measured in square units.
Let the length of the rectangle be L
The width of the rectangle is W
The length of a rectangle is twice its width
L = 2W
Perimeter of the Rectangle is 2( Length + Width)
30 = 2 (L +W)
15 = L + W
15 = 2W +W
15 = 3W
W = 5m
L = 10m
The area of the rectangle is Length * Width
Area = 10 *5
Area = 50 sq.m
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Take thus quote, and embed (introduce) it into a complete sentence: "TV plots
and characters tended to be simple" The author is Ostergaard.
What is the volume of a sphere, to the nearest cubic inch, if the radius is 16 inches? Use π = 3.14.
Answer:
vol = 17,148 cu. in.
Step-by-step explanation:
vol = 4 / 3 * pi * r³
vol = 4 / 3 *3.14 * 16³
vol = 17,148 cu. in.
Answer:
The answer is
17149 cubic inchesStep-by-step explanation:
Volume of a sphere is given by
[tex]V = \frac{4}{3} \pi {r}^{3} [/tex]
where r is the radius of the sphere
π = 3.14
From the question
r = 16 inches
Volume of the sphere is
[tex]V = \frac{4}{3} (3.14) {16}^{3} [/tex]
V = 17148.586
We have the final answer as
V = 17149 cubic inches to the nearest cubic inch
Hope this helps you
