A company that produces DVD drives has a 12% defective rate. Let X represent the number of defectives in a random sample of 55 of their drives.

Required:
a. What is the probability the sample will contain exactly 8 defective drives?
b. What is the probability the sample will contain more than 8 defective drives?
c. What is the probability the sample will contain less than 8 defective drives?
d. What is the expected number of defective drives in the sample?

Answers

Answer 1

Answer:

a) 0.1287 = 12.87% probability the sample will contain exactly 8 defective drives

b) 0.2092 = 20.92% probability the sample will contain more than 8 defective drives.

c) 0.6621 = 66.21% probability the sample will contain less than 8 defective drives.

d) The expected number of defective drives in the sample is 6.6

Step-by-step explanation:

For each DVD, there are only two possible outcomes. Either it is defective, or it is not. The probability of a DVD being defective is independent of any other DVD, which means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [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]

And p is the probability of X happening.

A company that produces DVD drives has a 12% defective rate.

This means that [tex]p = 0.12[/tex]

Let X represent the number of defectives in a random sample of 55 of their drives.

This means that [tex]n = 55[/tex]

a. What is the probability the sample will contain exactly 8 defective drives?

This is [tex]P(X = 8)[/tex]. So

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 8) = C_{55,8}.(0.12)^{8}.(0.88)^{47} = 0.1287[/tex]

0.1287 = 12.87% probability the sample will contain exactly 8 defective drives.

b. What is the probability the sample will contain more than 8 defective drives?

This is:

[tex]P(X > 8) = 1 - P(X \leq 8)[/tex]

In which:

[tex]P(X \leq 8) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5) + P(X = 6) + P(X = 7) + P(X = 8)[/tex]

Then

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 0) = C_{55,0}.(0.12)^{0}.(0.88)^{55} = 0.0009[/tex]

[tex]P(X = 1) = C_{55,1}.(0.12)^{1}.(0.88)^{54} = 0.0066[/tex]

[tex]P(X = 2) = C_{55,2}.(0.12)^{2}.(0.88)^{53} = 0.0244[/tex]

[tex]P(X = 3) = C_{55,3}.(0.12)^{3}.(0.88)^{52} = 0.0588[/tex]

[tex]P(X = 4) = C_{55,4}.(0.12)^{4}.(0.88)^{51} = 0.1043[/tex]

[tex]P(X = 5) = C_{55,5}.(0.12)^{5}.(0.88)^{50} = 0.1450[/tex]

[tex]P(X = 6) = C_{55,8}.(0.12)^{6}.(0.88)^{49} = 0.1648[/tex]

[tex]P(X = 7) = C_{55,7}.(0.12)^{7}.(0.88)^{48} = 0.1573[/tex]

[tex]P(X = 8) = C_{55,8}.(0.12)^{8}.(0.88)^{47} = 0.1287[/tex]

So

[tex]P(X \leq 8) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5) + P(X = 6) + P(X = 7) + P(X = 8) = 0.0009 + 0.0066 + 0.0244 + 0.0588 + 0.1043 + 0.1450 + 0.1648 + 0.1573 + 0.1287 = 0.7908[/tex]

[tex]P(X > 8) = 1 - P(X \leq 8) = 1 - 0.7908 = 0.2092[/tex]

0.2092 = 20.92% probability the sample will contain more than 8 defective drives.

c. What is the probability the sample will contain less than 8 defective drives?

This is:

[tex]P(X < 8) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5) + P(X = 6) + P(X = 7)[/tex]

With the values we found in b.

[tex]P(X < 8) = 0.0009 + 0.0066 + 0.0244 + 0.0588 + 0.1043 + 0.1450 + 0.1648 + 0.1573 = 0.6621[/tex]

0.6621 = 66.21% probability the sample will contain less than 8 defective drives.

d. What is the expected number of defective drives in the sample?

The expected value of the binomial distribution is:

[tex]E(X) = np[/tex]

In this question:

[tex]E(X) = 55(0.12) = 6.6[/tex]

The expected number of defective drives in the sample is 6.6


Related Questions

In factons you divide the numerator and the whole number .. then denominator

Correct?

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Answer:

Step-by-step explanation:

yes

identify the angles relationship

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Answer:

Adjacent

Step-by-step explanation:

Adjacent angles are two angles that have a common vertex and a common side but do not overlap

Which is heavier, 4- kilograms
or
4
4 kilograms?

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Answer:

i think 4 4 kilograms if im wrong sorry

Step-by-step explanation:

Factor 12x-40 using the gcf

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Answer:

4(3x-10)

Step-by-step explanation:

12x-40 = (4*3)x-(4*10) = 4(3x-10). The GCF is 4.

Hiiii can u please pls pls pls

Answers

Answer:

x | y

0 | 0

6 | 2

12 | 4

Step-by-step explanation:

Multiply each x value in the table by 1/3 to get 0, 2, and 4 for your y values.

Answer:

x    y

0    0

6    2

12   4

Step-by-step explanation:

Is means equals

The equation is

y = 1/3 x

Let x = 0

y = 1/3 (0) = 0

Let x = 6

y = 1/3 (6) = 2

Let x = 12

y = 1/3 (12) = 4

The population of the world in 1987 was 5 billion and the annual growth rate was estimated at 2 percent per year. Assuming that the world population follows an exponential growth model, find the projected world population in 2015

Answers

Answer:

The projected world population in 2015 was 8,705,121,030 people.

Step-by-step explanation:

Given that the population of the world in 1987 was 5 billion and the annual growth rate was estimated at 2 percent per year, assuming that the world population follows an exponential growth model, to find the projected world population in 2015 the following calculation must be performed :

5,000,000,000 x 1.02 ^ (2015-1987) = X

5,000,000,000 x 1.02 ^ 28 = X

5,000,000,000 x 1.741024 = X

8,705,121,030 = X

Therefore, the projected world population in 2015 was 8,705,121,030 people.

A business rents in-line skates and bicycles to tourists on vacation. A pair of skates rents for $5 per day. A bicycle rents for $20 per day.
On a certain day, the owner of the business has 25 rentals and takes in $425.
Write a system of equation to represent this situation, then solve to find the number of each item rented.
Show both the equations and the solution.

Answers

Answer:

5x+20y=425

Step-by-step explanation:

Its 5 bucks for x pairs of skates

Its 20 dollars for y bikes

x+y rentals have to equal 25

all of this is equal to 425. All that is left to do is test with number until the statement is true.

try :

5(5)+(20)(20)=425

x + y do equal 25, and the total is equal to 425.

I need some help! thank you!

Answers

Answer:

The 1st,Thrid, Fifth Option

Step-by-step explanation:

The first option is true. We can move the orginal square root function to get g(x).

The second option is false. Function g(x) which equals

[tex] \sqrt{x - 3} - 1[/tex]

Domain is all real numbers greater than or equal to 3.

The third option is true. Since minimum point we can get is 0 in a square root function. We have a vertical shift so our new minimum point is

[tex]0 - 1 = - 1[/tex]

We can take the sqr root of 0 so

So all real numbers that are greater than or equal to -1 is true.

The fourth option is false, we need to add 3 instead of subtract 3.

The fifth option is true, we can do that to get back to our original function

Determine if the two figures are congruent and explain your answer.

Answers

Answer: Yes they are

Explanation: All respective sides have the same slope
Yes they are

The slope of the shapes are congruent.

What is the simplified expression for the
expression below? 4(x+8)+5(x-3)

Answers

4(x+8)+5(x-3)
= 4x+32+5(x-3)
=4x+32+5x-15
=9x+17

Answer: 9x+17

What is the product?
(-2d^2+5)(5d^2-6s)

Answers

Answer:

= -10d^4 + 12d^2s + 25d^2 - 30s

If he is correct, what is the probability that the mean of a sample of 68 computers would differ from the population mean by less than 2.08 months

Answers

Complete Question

The quality control manager at a computer manufacturing company believes that the mean life of a computer is 91 months with a standard deviation of 10 months if he is correct. what is the probability that the mean of a sample of 68 computers would differ from the population mean by less than 2.08 months? Round your answer to four decimal places. Answer How to enter your answer Tables Keypad

Answer:

[tex]P(-1.72<Z<1.72)=0.9146[/tex]

Step-by-step explanation:

From the question we are told that:

Population mean \mu=91

Sample Mean \=x =2.08

Standard Deviation \sigma=10

Sample size n=68

Generally the Probability that The  sample mean  would differ from the population mean

P(|\=x-\mu|<2.08)

From Table

[tex]P(|\=x-\mu|<2.08)=P(|z|<1.72)[/tex]

T Test

[tex]Z=\frac{\=x-\mu}{\frac{\sigma}{\sqrt{n} } }[/tex]

[tex]Z=\frac{2.08}{\frac{10}{\sqrt{68} } }[/tex]

[tex]Z=1.72[/tex]

[tex]P(|\=x-\mu|<2.08)=P(|z|<1.72)[/tex]

[tex]P(-1.72<Z<1.72)[/tex]

Therefore From Table

[tex]P(-1.72<Z<1.72)=0.9146[/tex]

Let f(x) = 5 + 12x − x^3. Find (a) the x- coordinate of all inflection points, (b)
the open intervals on which f is concave up, (c) the open intervals on which
f is concave down.

Answers

Answer:

A) x = 0.

B) f is concave up for (-∞, 0).

C) f is concave down for (0, ∞).

Step-by-step explanation:

We are given the function:

[tex]f(x)=5+12x-x^3[/tex]

A)

We want to find the x-coordinates of all inflection points.

Recall that inflections points (may) occur when the second derivative equals zero. Hence, find the second derivative. The first derivative is given by:

[tex]f'(x) = 12-3x^2[/tex]

And the second:

[tex]f''(x) = -6x[/tex]

Set the second derivative equal to zero:

[tex]0=-6x[/tex]

And solve for x. Hence:

[tex]x=0[/tex]

We must test the solution. In order for it to be an inflection point, the second derivative must change signs before and after. Testing x = -1:

[tex]f''(-1) = 6>0[/tex]

And testing x = 1:

[tex]f''(1) = -6<0[/tex]

Since the signs change for x = 0, x = 0 is indeed an inflection point.

B)

Recall that f is concave up when f''(x) is positive, and f is concave down when f''(x) is negative.

From the testing in Part A, we know that f''(x) is positive for all values less than zero. Hence, f is concave up for all values less than zero. Our interval is:

[tex](-\infty, 0)[/tex]

C)

From Part A, we know that f''(x) is negative for all values greater than zero. So, f is concave down for that interval:

[tex](0, \infty)[/tex]

Lisa reads an equal number of pages of a book every week. The graph below shows the number of pages of the book left to read, y, after x weeks:

A graph titled Lisas Book Reading shows Number of Weeks on the x-axis and Number of Pages Left on the y-axis. The scale on the x-axis shows numbers from 0 to 6 at increments of 1, and the scale on the y-axis shows numbers from 0 to 350 at increments of 50. A straight line joins the ordered pairs 0, 250 and 1, 200 and 2, 150 and 3, 100 and 4, 50 and 5, 0.

Which equation best models the relationship between x and y?

y = −50x + 250
y = −5x + 50
y = −50x + 350
y = −5x + 250

Answers

9514 1404 393

Answer:

  (a)  y = −50x + 250

Step-by-step explanation:

In case you don't realize that the graph starts at 250 and decreases by 50 for each increase of 1 in x, you can see if any of the equations match the given points. The only one that does is the first one:

  y = -50x +250

Answer:

(a)  y = −50x + 250

Step-by-step explanation:

Suppose f(x)=x^2. What is the graph of g(x)=1/2f(x)?

Answers

9514 1404 393

Answer:

  see attached

Step-by-step explanation:

The graph of g(x) is a vertically scaled version of the graph of f(x). The scale factor is 1/2, so vertical height at a given value of x is 1/2 what it is for f(x). This will make the graph appear shorter and fatter than for f(x).

The graph of g(x) is attached.

A soft drink manufacturer wishes to know how many soft drinks adults drink each week. They want to construct a 95% confidence interval with an error of no more than 0.08. A consultant has informed them that a previous study found the mean to be 3.1 soft drinks per week and found the variance to be 0.49. What is the minimum sample size required to create the specified confidence interval? Round your answer up to the next integer.

Answers

Answer:

The minimum sample size required to create the specified confidence interval is 295.

Step-by-step explanation:

We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1 - 0.95}{2} = 0.025[/tex]

Now, we have to find z in the Z-table as such z has a p-value of [tex]1 - \alpha[/tex].

That is z with a pvalue of [tex]1 - 0.025 = 0.975[/tex], so Z = 1.96.

Now, find the margin of error M as such

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

Variance of 0.49:

This means that [tex]\sigma = \sqrt{0.49} = 0.7[/tex]

They want to construct a 95% confidence interval with an error of no more than 0.08. What is the minimum sample size required to create the specified confidence interval?

The minimum sample size is n for which M = 0.08. So

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

[tex]0.08 = 1.96\frac{0.7}{\sqrt{n}}[/tex]

[tex]0.08\sqrt{n} = 1.96*0.7[/tex]

[tex]\sqrt{n} = \frac{1.96*0.7}{0.08}[/tex]

[tex](\sqrt{n})^2 = (\frac{1.96*0.7}{0.08})^2[/tex]

[tex]n = 294.1[/tex]

Rounding up:

The minimum sample size required to create the specified confidence interval is 295.

A ball is thrown from an initial height of 7 feet with an initial upward velocity of 23 ft/s. The ball's height h (in feet) after 1 seconds is given by the following.
h = 7+23t-16t^2
Find all values of 1 for which the ball's height is 15 feet.

Answers

Answer:

Step-by-step explanation:

If we are looking for the time(s) that the ball is at a height of 15, we simply sub in a 15 for the height in the position equation and solve for t:

[tex]15=-16t^2+23t+7[/tex] and

[tex]0=-16t^2+23t-8[/tex]

Factor this however you factor a quadratic in class to get

t = .59 seconds and t = .85 seconds.

This means that .59 seconds after the ball was thrown into the air it was 15 feet off the ground. Then the ball reached its max height, gravity took over, and began pulling it back down to earth. The ball passes the height of 15 feet again on its way down after .85 seconds.

A research team is testing a product that will minimize wrinkles among older adults. Volunteers in the age group of 40 to 45 are included in the research. The research team gives a cream to be applied on the face to one group and a placebo cream to the other group.

Answers

What is the question?

The regression analysis can be summarized as follows: Multiple Choice No significant relationship exists between the variables. A significant negative relationship exists between the variables. For every unit increase in x, y decreases by 12.8094. A significant positive relationship exists between the variables

Answers

Answer:

A significant negative relationship exists between the variables

Step-by-step explanation:

Base on the information given in the question which goes thus : For every unit increase in x, y decreases by 12.8094. The value 12.8094 is the slope which is the rate of change in y variable per unit change in the independent variable. The sign or nature of the slope Coefficient gives an hint about the relationship between the x and y variables. The slope Coefficient in this case is negative and thus we'll have a negative relationship between the x and y variables (an increase in x leads to a corresponding decrease in y). This is a negative association.

The concentration of carbon monoxide (CO) in a gas sample is measured by a spectrophotometer and found to be 85 ppm. Through long experience with this instrument, it is believed that its measurements are unbiased and normally distributed, with an uncertainty (standard deviation) of 9 ppm. Find a 95% confidence interval for the concentration of CO in this sample. Round the answers to two decimal places. The 95% confidence interval is

Answers

Answer:

The confidence interval is [tex](85 - \frac{14.81}{\sqrt{n}},85 + \frac{14.81}{\sqrt{n}})[/tex], in which n is the size of the sample.

Step-by-step explanation:

We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1 - 0.95}{2} = 0.025[/tex]

Now, we have to find z in the Z-table as such z has a p-value of [tex]1 - \alpha[/tex].

That is z with a pvalue of [tex]1 - 0.025 = 0.975[/tex], so Z = 1.96.

Now, find the margin of error M as such

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

[tex]M = 1.645\frac{9}{\sqrt{n}} = \frac{14.81}{\sqrt{n}}[/tex]

The lower end of the interval is the sample mean subtracted by M. So it is [tex]85 - \frac{14.81}{\sqrt{n}}[/tex]

The upper end of the interval is the sample mean added to M. So it is [tex]85 + \frac{14.81}{\sqrt{n}}[/tex]

The confidence interval is [tex](85 - \frac{14.81}{\sqrt{n}},85 + \frac{14.81}{\sqrt{n}})[/tex], in which n is the size of the sample.

What is the solution to this equation?
6
O A. x = 18
O B. x= -2
O c. x= -18
O D. X= 21

Answers

Answer:

O C. x = -18

Step-by-step explanation:

x/-3 = 6

x = denominator multiplied by quotient.

x = -3 x 6

x = -18

write your answer in simplest radical form​

Answers

9514 1404 393

Answer:

  f = 3 units

Step-by-step explanation:

The ratios of side lengths in this 30°-60°-90° triangle are ...

  1 : √3 : 2

So, the ratio of interest is ...

  1 : √3 = √3 : f

We can see that the numbers in the second ratio are √3 times the numbers in the first ratio, so

  f = √3 × √3 = 3

  f = 3 units

By the third day of a particular week, 2 accidents have already occurred in the intersection. What is the probability that there will be less than a total of 4 accidents during that week

Answers

Answer:

The right answer is "0.70".

Step-by-step explanation:

The given query seems to be incomplete. Please find below the attachment of the full query.

By using the Bayes' theorem, we get

⇒  [tex]P[(X<4)|(X \geq 2)] = \frac{P(2 \leq X < 4)}{P(X \geq 2)}[/tex]

By putting the values, we get

                                     [tex]=\frac{[P(2)+P(3)]}{[1-P(0)-P(1)]}[/tex]

                                     [tex]=\frac{(0.20+0.15)}{1-0.20-0.30}[/tex]

                                     [tex]=\frac{0.35}{0.5}[/tex]

                                     [tex]=0.70[/tex]

Use the functions below to complete Parts 1 and 2.

f(x)= |x| g(x)= |x+2| - 3

Part 1: Graph f(x) and g(x) on the grid below. Label each graph.

HINT: Making a table of values for each function may help you to graph them.

Part 2: describe how the graph of g(x) relates to the graph of its parent function, f(x).

HINT: Think about how f(x) was shifted to get g(x).

Answers

9514 1404 393

Answer:

  1. see below

  2. g(x) is f(x) translated left 2 and down 3

Step-by-step explanation:

1. The graphs are attached. F(x) is in red; g(x) is in blue.

__

2. The graph of g(x) = f(x -h) +k is the parent function translated by (h, k). Here we have (h, k) = (-2, -3), so g(x) is f(x) translated left 2 and down 3.

Which statement is true about the net and the solid it can form?



A. The length of side a will be 5 m.

B. The length of side b will be 2 m.

C. The length of side c will be 7 m.

D. The length of side c will be 2 m.

Answers

Step-by-step explanation:

Option B

The length of side will be 2m...

hope it helps

The answer is C hope it help

You want to walk from home to a clothing store that is 1/4 miles away you stop for a rest after 1/8 miles how much farther do you have to walk

Answers

Answer:

1/8

Step-by-step explanation:

Answer: 1/8

Step-by-step explanation:

1/8 + 1/8 = 2/8 = 1/4

People's movements between places is called

Answers

Answer:

The three answers I can think of are migration, immigration, and emigration.

Step-by-step explanation:

Hope this helps!

spatial interaction. The movement ( e.g. of people, goods, information ) between different places; an indication of interdependence between different geographic locations or areas

Evaluate − x 2 −5 y 3 when x = 4 and y =−1

Answers

Answer:

-11

Step-by-step explanation:

I am going to assume that it is -x^2-5y^3.

-(4^2)-5(-1^3)

-16-5(-1)

-16+5

-11

Answer:

- 11

Step-by-step explanation:

If x = 4,  y = -1

then,

        - x^2 - 5y^3 = - (4)^2 - 5(-1)^3

                            = - 16 + 5

                            = - 11

A sporting goods store manager was selling a ski set for a certain price. The manager offered the markdowns​ shown, making the​ one-day sale price of the ski set ​$324. Find the original selling price of the ski set.

Answers

Answer:

$520.632

Step-by-step explanation:

520 and some change

(2/3)^x-1=27/8, Find x​

Answers

You’re answer will be “x=-2”
See the attached photo for the answer

Hope this helps! Please make me the brainliest, it’s not necessary but appreciated, I put a lot of effort and research into my answers. Have a good day, stay safe and stay healthy.
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