A Government company claims that an average light bulb lasts 270 days. A researcher randomly selects 18 bulbs for testing. The sampled bulbs last an average of 260 days, with a standard deviation of 90 days. If the CEO's claim were true, what is the probability that 18 randomly selected bulbs would have an average life of no more than 260 days

Answers

Answer 1

Answer:

31.92% probability that 18 randomly selected bulbs would have an average life of no more than 260 days

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution

When the distribution is normal, we use the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

In this question, we have that:

[tex]\mu = 270, \sigma = 90, n = 18, s = \frac{90}{\sqrt{18}} = 21.2[/tex]

What is the probability that 18 randomly selected bulbs would have an average life of no more than 260 days?

This is the pvalue of Z when [tex]X = 260[/tex]. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{260 - 270}{21.2}[/tex]

[tex]Z = -0.47[/tex]

[tex]Z = -0.47[/tex] has a pvalue of 0.3192.

31.92% probability that 18 randomly selected bulbs would have an average life of no more than 260 days


Related Questions

Whoever answers it first gets the title brainliest.

Answers

Answer:

2.24

Explanation:

2.5 - 2.4 / 1.2(0.13) = 2.24

Jorge can travel 50 miles on his
motorized scooter using 1 gallon of gas.
How many miles can he travel using
8 gallons of gas?

Answers

Answer:

its c

Step-by-step explanation:

Answer:

400 miles

Step-by-step explanation:

50 miles.....1 gallon

x miles......8 gallons

50*8=400

Pls help urgently extra points and mark brainlist easy reading

Answers

Answer:

isolated

Step-by-step explanation:

It means private, or isolated

please help ASAP 25 pts + brainliest, please show or explain answer

Answers

Answer:

B. .60

Step-by-step explanation:

With reference angle A

perpendicular (p) = 6

hypotenuse (h) = 10

Then

Sin A

= p/h

= 6 / 10

= 0.6

Answer:

Option B

Step-by-step explanation:

We know that

[tex] \sin( \alpha ) = \frac{side \: opposite \: to \: \alpha }{hypotenuse \: of \: triangle} [/tex]

where [tex] \ alpha [/tex] is an angle of a triangle.

In the triangle given above , [tex] \ alpha = angle A [/tex]. So,

[tex] \sin(a) = \frac{6}{10} = 0.60[/tex]

Read the article below carefully and answer the question that follows.

On the morning of July 15, 2006, fourteen school buses were vandalized. The buses, property of Walt Whitman Middle School, were parked in the "bus barn" on campus. The vandals spray-painted the buses with pictures of dogs. Dogs happen to be the mascot of rival school Edgar Allan Poe Academy. This has led some to believe that some students from EAPA may be the culprits in the incident. Says the mother of one Walt Whitman student, "Oh, yeah, the [Edgar Allan] Poe [Academy] kids are definitely responsible. Those kids don't have any discipline, and they're still stewing over the loss of last week's football game." Police, however, say that they currently have no suspects.

This article is probably NOT from a mainstream news source.

True
False

Answers

I would say the answer is true, if it’s not I apologize

Find the unknown angle measure by solving for the given variable.

Answers

Answer:

10 1/2

Step-by-step explanation:

make b the subject of the formula a=squareroot of b+16

Answers

Step-by-step explanation:

a=

[tex] a = \sqrt{b + 16} \\ a { }^{2} = b + 16 \\ b = a {}^{2} - 16[/tex]

What percentage of the students surveyed eat no more than 3 whole servings of fruits and vegetables daily

Answers

Answer:

Step-by-step explanation:

The missing histogram file is attached in the image below.

From the graph, deduce that:

the servings of fruits and vegetable                     number of students

0                                                                             1

1                                                                             4

2                                                                             5

3                                                                             10

4                                                                             8

5                                                                             3

6                                                                             0

7                                                                             1

Thus, the percentage of students surveyed that eat more than 3 whole servings is:

= starting from 4 = (8+3+0+1)/32 = 0.375

2.7.–2.5 = 6.75

A . agree

b. disagree; a negative times a negative is positive
C. disagree; a positive times a negative is negative.
PLEASE answer quick ​

Answers

The answer to this is about c

Solve for x x/12+6=8

x=​

Answers

Answer:

X=24

Step-by-step explanation:

X/12 + 6 = 8

we can multiply the equation to 12 to make it simple. We get:

X + 72 = 96

So X = 96-72=24

an oil tank loses 32% of its contents every hour. Peter says the tank will have lost 95% of its original contents by the end of the sixth hour. Is peter correct

Answers

Answer:

it lose 90 percent in 3 hours so peter is incorrect

Step-by-step explanation:

List the number from least to greatest.

Answers

Answer:

1. $1430

2. $930

3. $1070

4. 105

   96

  -20

  -76

  -560

what is 25% of 12???

Answers

Answer:

3

Step-by-step explanation:

%25 is 1/4

1/4 of 12 is 3

Answer:

3

Step-by-step explanation:

25% is equal to 1/4. Of means multiply. Therefore, you would just multiply 1/4 and 12. Your answer should be 3.

Ariana went shopping for a new video game. The listed price of the video game was
$36, but the price with tax came to $37.08. Find the percent sales tax.

Answers

Answer:

I think it should be around 0.03%

Step-by-step explanation:

hope that helps:)))

Answer:

3%

Step-by-step explanation:

Anybody can help with these 2 I would really appreciate it for my last grade

Answers

Answer:

575x.25=143.75   575-143.75=$431.25

21.95x.15=$3.29 tip total bill $25.24

Step-by-step explanation:

Find the unit rate. 210 miles in 7 hours

That means you need to find out how many miles are traveled in 1 hour.

Your answer should be written like this: ____ miles in 1 hour OR ____miles per hour OR ____ mph and you need to fill in the blank with your answer!

Answers

Answer:

the answer will be 30 mikes per hour

Step-by-step explanation:


Andrea paid $60.75 for 9 sandwiches. Each sandwich costs the same amount.
Use the drop down menus to write an equation for the price, p, of one sandwich.

P x _______=____??

Answers

Answer:

Px9=60.75

Step-by-step explanation:

An angle measures 80° less than the measure of its complementary angle. What is the measure of each angle

Answers

Answer:

let the angle be x and the complementary angle be y

so, x+y=90 and given,

x=y-80

solving both the equations,

x = 5

y = 85

so the angles are 5 and 85

On a coordinate plane, point A is 7 units to the left. Point B is at (0, 0). Point C is 7 units to the right. Point D is 7 units up .Point E is 7 units down.
Which point is located at (0, –7)?

Answers

Answer:

E

Step-by-step explanation:

The point (0, 7) in located in the 1st quadrant

PLS HELP PLSPLSPLS thank you!!!!

Answers

The correct is answer either c or b.
I think it is B?????

Each letter in SYNONYM is written on a piece of paper and randomly chosen from a bag.What are the odds for choosing an Y?

Answers

2/7 or 2:7 or about 28.5%

Answer: 2/7 or 2 out of 7

Step-by-step explanation: because there are 2 y's in the word synonym

What c-value makes the set of ratios equivalent. HELP ASAP

Answers

Answer:

6 ---------> 2x : 48 = 3 : 12

9 --------->   2 : 3 = 6 : x

16 -------->  12 : 15 = x : 20

24 ------->  4 : 7  = x : 42

Step-by-step explanation:

What is 10x9 and 9x10

Answers

Answer:

90 for both of them

Answer:

90

Step-by-step explanation:

1+1+1+1+1+1+1+1+1=9 then add a 0

put the numbers in
order
2.6
6.2
2.06
0.62​

Answers

Answer:

Put the numbers in

order

2.6

6.2

2.06

0.62​

Step-by-step explanation:

Answer:

If your looking for the answers from least to greatest it goes,

0.62, 2.06, 2.6, 6.2

Consider the monthly payment formula M=Pr(1+r)^n/(1+r)^n-1. what is the name of the formula you get if you solve for P? what about if you solve for n? what special function do you need to use when solving for n?

WRITTEN RESPONSE QUESTION PLEASE ANSWER ASAP WILL AWARD BRAINLIEST.

Answers

Answer:

0.0061

Step-by-step drip check:

The name of the formula you get if you solve for P could be "Principal (loan amount)" "Term of the loan (in months)" or "Number of monthly payments"

Logarithms;

[tex]n = \dfrac{ ln[1 - \dfrac{Pr}{M} ]}{ln(1+r)}[/tex]

What is Monthly Payment Formula?

Consider the monthly payment formula

[tex]M= \dfrac{Pr(1+r)^n}{(1+r)^n-1}[/tex]

where: M = monthly payment.

P = principal loan amount.

r = interest rate per month (in decimal form).

n = term of the loan (in months).

If we will solve for P, the name of the formula is "Principal (loan amount)".

If we solve for n, the formula is "Term of the loan (in months)" or "Number of monthly payments".

When solving for n, we have to use logarithms:

[tex]M (1+r)^n-1=Pr(1+r)^n\\\\\dfrac{1}{ (1+r)^n} = 1 - \dfrac{Pr}{M} \\\\ln\dfrac{1}{ (1+r)^n} = ln[1 - \dfrac{Pr}{M} ]\\\\\\n = \dfrac{ ln[1 - \dfrac{Pr}{M} ]}{ln(1+r)}[/tex]

Learn more about monthly payments questions;

https://brainly.com/question/29766847

#SPJ2



Find the perimeter of the figure to the right

6 yards
8 4/5 yard
9 2/3 yards
8 yards

Answers

I need to see the figure to answer the question

Someone please help me with this question

Answers

Answer:

Jinsoul from Loona

Step-by-step explanation:

In order to solve this problem, you must do the famous math operation: Jinsoul from Loona

Have a nice day!

Use the geometric mean (altitude) theorem. What is the value of m?​

Answers

Answer:4

Step-by-step explanation:

Answer:

Correct answer is c

Step-by-step explanation:

just took the test

8 Classes
G how to change you..
3. Using the graph provided determine the experimental probability,
expressed as a reduced fraction, of rolling 1 or 5 when a number cube is
rolled 50 times.*
20 points
Number Cube Experiment
14
12
10
10
9
8
6
Number of Rolls
O NO
6
2. 3
5
Number Showing

Answers

Answer:

14

Step-by-step explanation:

The correct Answer is 14

The scatter plot shows a correlation between the number of participants and the year of
the snowboarding competition.
The line of regression models that correlation.
Enter a number to complete each statement.

Answers

Answers:

In 2003, there were 32 ...

The model predicts ... 40 ...

... 8 below what the model predicted

In 2003, there were 32 ...

-> We find the x-axis of 2003 and look up until we hit the line, then we find the y-coordinate for that point

-> 32

The model predicts ... 40 ...

-> The green 8 with an arrow shows the prediction

-> 40 - 8 = 32

-> 40

... 8 below what the model predicted

-> The green 8 shows the difference in the prediction and the actual participation

-> 8

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