Answer:
Reject H₀.
Step-by-step explanation:
In this case, we need to test whether the average student spent less than the recommended amount of time doing homework in statistics.
The provided data is:
S = {20, 29, 28, 22, 26, 22, 22, 18, 23, 21, 20, 27}
Compute the sample mean:
[tex]\bar x=\frac{1}{n}\sum X=\frac{1}{12}\cdot [20+29+...+27]=23.167[/tex]
The population standard deviation is σ = 7.
The hypothesis for the test is:
H₀: The average student does not spent less than the recommended amount of time doing homework, i.e. μ ≥ 24.
Hₐ: The average student spent less than the recommended amount of time doing homework, i.e. μ < 24.
(A)
Compute the standardized test statistic value as follows:
[tex]z=\frac{\bar x-\mu}{\sigma/\sqrt{n}}[/tex]
[tex]=\frac{23.167-24}{7/\sqrt{12}}\\\\=-0.412[/tex]
Thus, the standardized test statistic value is -0.412.
(B)
The significance level of the test is:
α = 0.07
The critical value of z is:
z₀.₀₇ = -1.476
The rejection region is:
(-∞, -0.1476)
(C)
Compute the p-value as follows:
[tex]p-value=P(Z<-0.412)=0.34[/tex]
*Use a z-table.
Thus, the p-value is 0.34.
(D)
Since, p-value = 0.34 > α = 0.07, the null hypothesis was failed to be rejected at 7% level of significance.
Thus, the correct option is (A).
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:
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.
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
Halla x si:
a) 4√5 b) √5 c) 4√3 d) 4 e) 4√2
Answer:
Option A. 4√5
Step-by-step explanation:
To obtain the value of x, we must first obtain the value of y as shown in the attached photo.
The value of y can be obtained by using the pythagoras theory as illustrated below:
In this case y is the longest side i.e the Hypothenus.
y² = 4² + [4√3]²
y² = 4² + [4² × (√3)²]
y² = 4² + [4² × 3]
y² = 16 + [16 × 3]
y² = 16 + 48
y² = 64
Take the square root of both side
y = √64
y = 8
Finally, we shall determine the value of x by using the pythagoras theory as illustrated below.
Note: x is the longest side i.e the Hypothenus in this case.
x² = 4² + 8²
x² = 16 + 64
x² = 80
Take the square root of both side
x = √80
x = √(16 × 5)
x = √16 × √5
x = 4√5
Therefore, the value of x is 4√5.
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°
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]
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
(a) A survey of the adults in a town shows that 8% have liver problems. Of these, it is also found that 25% are heavy drinkers, 35% are social drinkers and 40% are non-drinkers. Of those that did not suffer from liver problems, 5% are heavy drinkers, 65% are social drinkers and 30% do not drink at all. An adult is chosen at random, what is the probability that this person i. Has a liver problems? (3 Marks) ii. Is a heavy drinker (2 Marks) iii. If a person is found to be a heavy drinker, what is the probability that this person has liver problem? (2 Marks) iv. If a person is found to have liver problems, what is the probability that this person is a heavy drinker? (2 Marks) v. If a person is found to be a non –drinker, what is the probability that this person has liver problems. (2 Marks)
Answer:
i. Has a liver problems?
= 0.08
ii. Is a heavy drinker ?
= 0.066
iii. If a person is found to be a heavy drinker, what is the probability that this person has liver problem?
= 0.303
iv. If a person is found to have liver problems, what is the probability that this person is a heavy drinker?
= 0.25
v. If a person is found to be a non –drinker, what is the probability that this person has liver problems?
= 0.104
Step-by-step explanation:
We have 2 Events in this question
Event A: People with liver problems
Event B : People without liver problems
Event A: People with liver problems
Let us represent people with liver problems as = (L)
a)8% have liver problems. = P(L)
Under liver problems we have:
b) 25% are heavy drinkers = P( L & H)
c) 35% are social drinkers = P( L & S)
d) 40% are non-drinkers. = P( L & N)
Event B( no liver problem)
Let us represent no liver problem as NL
We are not given in the question but Probability of having no liver problem = 100 - Probability of having liver problem
= 100 - 8% = 92 %
P(NL ) = 92%
From the question, For people without liver problems, we have:
a) 5% are heavy drinkers = P(NL & H)
b) 65% are social drinkers = P( NL & S)
c) 30% do not drink at all = P( NL & N)
An adult is chosen at random, what is the probability that this person
i. Has a liver problems?
P(L) = 8% or 0.08
ii. Is a heavy drinker ?
From the question, we have:
Probability of people that have liver problems and are heavy drinkers P(L & H) = 25% = 0.25
Probability of people that have do not have liver problems and are heavy drinkers P(NL & H) = 5% = 0.05
Probability ( Heavy drinker) =
P(L) × P(L & H) + P(NL) × P(NL & H)
= 0.25 × 0.08 + 0.05 × 0.92
= 0.066
iii. If a person is found to be a heavy drinker, what is the probability that this person has liver problem?
Probability (Heavy drinker and has liver problem) = [P(L) × P(L & H)] ÷ [P(L) × P(L & H)] + [P(NL) × P(NL & H) ]
= [0.25 × 0.08] ÷ [0.25 × 0.08] + [0.05 × 0.92]
= 0.303030303
Approximately = 0.303
iv. If a person is found to have liver problems, what is the probability that this person is a heavy drinker?
P(L & H) = 25% = 0.25
v. If a person is found to be a non –drinker, what is the probability that this person has liver problems.?
People with liver problems are non-drinkers. = P( L & N) = 40% = 0.4
People without liver problems and do not drink at all = P( NL & N) = 30% = 0.3
Probability (non drinker and has liver problem) = [P( L & N) × P(L & H)] ÷ [P( L & N) × P(L & H)] + [ P( NL & N) × P(NL & H) ]
= [0.4× 0.08] ÷ [0.4 × 0.08] + [0.3 × 0.92]
= 0.1038961039
Approximately ≈ 0.104
Isreal spends the most time on social media with a total of 11.1.peru has a total of 8.3 how much more time does israel spend on social media
Answer:
2.8
Step-by-step explanation:
11.1-8.3=2.8
HOPE I HELPED
PLS MARK BRAINLIEST
DESPERATELY TRYING TO LEVEL UP
✌ -ZYLYNN JADE ARDENNE
JUST A RANDOM GIRL WANTING TO HELP PEOPLE!
PEACE!
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
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.
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 :)
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
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
A coin is tossed 4 times. Let E1 be the event "the first toss shows heads" and E2 the event "the second toss shows heads" and so on. That is, Ei is the event that the "i"th toss shows up heads.
A. Are the events e e and f f independent?
B. Find the probability of showing heads on both toss.
Answer:
The events are independent.
The probability of showing heads on both toss is equal to 1/2
Step-by-step explanation:
The sample space for this experiment consists of 2⁴= 16 sample points, as each toss can result in two outcomes we assume that the events are equally likely.
Two events are independent in the sample space if the probability of one event occurs, is not affected by whether the other event has or has not occurred.
In general the k events are defined to be mutually independent if and only if the probability of the intersection of any 2,3,--------, k equals the product of their respective probabilities.
P (A∩B) = P(A). P(B)
P (A∩B) = 1/2. 1/2= 1/4
Head Tail
P(E1)= 1/2 ---------- Coin 1 H,H T,H
1/4 1/4
P(E2)= 1/2 --------------- Coin 2 H, H H,T
1/4 1/4
So the events are independent.
The probability of showing heads on both toss is equal to 1/2
The sample space for this experiment consists of 2⁴= 16 sample points, out of which eight will have heads on both toss.
Or in other words ( 1/4* 1/4) = 2/4 = 1/2
A tin of tennis balls costs $6.99, and each tin contains 4
tennis balls.
If the tennis balls were sold individually, then
approximately how much would one tennis ball cost?
$
Answer:
About $1.75 per tennis balls
Step-by-step explanation:
A tin of 4 tennis balls costs $6.99. We are asked to find the price of one tennis ball.
We need to find the unit price, or price per ball.
Divide the cost by the number of tennis balls.
cost / tennis balls
cost = $6.99
tennis balls = 4 tennis balls
$6.99 / 4 tennis balls
Divide 6.99 by 4.
$1.7475 / 1 tennis ball
Round to the nearest cent or hundredth. The 7 in the thousandth place tells us to round the 4 to a 5 in the hundredth place.
$1.75 / 1 tennis ball
It would cost approximately $1.75 for one tennis ball.
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.
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.
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
how many pounds are in 2 tons 1,760 ounces
Answer:
4110
Step-by-step explanation:
One ton is equal to 2000 pounds and one ounce is equal to 0.0625 pounds.
2 tons*2000 lbs per ton = 4000 lbs
1760 ounces*0.0625 lebs per ounce = 110 lbs
4000+110=4110 lbs
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
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
This person made a mistake. what is the mistake and what is the correct answer?!!
Answer: 44
Step-by-step explanation:
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]
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.
Help me solve this!!!
Answer:
m∠AOD = 140°
Step-by-step explanation:
In the diagram attached,
OA⊥OC and OB⊥OD
m∠AOD = 3.5(m∠BOC)
Since, m∠BOD = 90° [Given: OA⊥OC]
m∠BOC + m∠COD = 90° ---------(1)
Similarly, m∠AOC = 90° [Given : OA⊥OC]
m∠AOB + m∠BOC = 90° --------(2)
Equation (1) - Equation(2)
(m∠BOC + m∠COD) - (m∠AOB + m∠BOC) = 90°- 90°
m∠COD = m∠AOB
m∠AOB + m∠BOC + m∠COD = m∠AOD --------(3)
m∠AOB + m∠BOC + m∠AOB = 3.5(m∠BOC) [Since m∠COD = m∠AOB]
2m∠AOB = 3.5(m∠BOC) - m∠BOC
2m∠AOB = 2.5(m∠BOC)
m∠AOB = 1.25(m∠BOC)
From equation (2),
m∠AOB + m∠BOC = 90°
1.25(m∠BOC) + m∠BOC = 90°
2.25(m∠BOC) = 90°
m∠BOC = 40°
From equation (1),
m∠BOC + m∠COD = 90°
m∠COD + 40° = 90°
m∠COD = 50°
Now by putting these values in equation (3)
m∠AOB + m∠BOC + m∠COD = m∠AOD
m∠COD + m∠BOC + m∠COD = m∠AOD
50° + 40° + 50°= m∠AOD
m∠AOD = 140°
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]
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
[tex]f(x) = {x}^{2} + 4x - 5[/tex] ; >-2
Find [tex] \frac{d {f}^{ - 1} }{dx} [/tex] at x=16
Please show solving
The inverse function theorem says
[tex]\dfrac{\mathrm df^{-1}}{\mathrm dx}(16)=\dfrac1{\frac{\mathrm df}{\mathrm dx}(f^{-1}(16))}[/tex]
We have
[tex]f(x)=x^2+4x-5[/tex]
defined on [tex]x>-2[/tex], for which we get
[tex]f^{-1}(x)=-2+\sqrt{x+9}[/tex]
and
[tex]f^{-1}(16)=-2+\sqrt{16+9}=3[/tex]
The derivative of [tex]f(x)[/tex] is
[tex]f'(x)=2x+4[/tex]
So we end up with
[tex]\dfrac{\mathrm df^{-1}}{\mathrm dx}(16)=\dfrac1{\frac{\mathrm df}{\mathrm dx}(3)}=\dfrac1{10}[/tex]
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
