The mean life expectancy of a certain type of light bulb is 945 hours with a standard deviation of 21 hours. What is the approximate standard deviation of the sampling distribution of the mean for all samples with n

Answers

Answer 1

Answer:

The approximate standard deviation of the sampling distribution of the mean for all samples of size n is [tex]s = \frac{\sigma}{\sqrt{n}} = \frac{21}{\sqrt{n}}[/tex]

Step-by-step explanation:

Central Limit Theorem

The Central Limit Theorem establishes 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.

The mean life expectancy of a certain type of light bulb is 945 hours with a standard deviation of 21 hours

This means that [tex]\mu = 945, \sigma = 21[/tex].

What is the approximate standard deviation of the sampling distribution of the mean for all samples of size n?

[tex]s = \frac{\sigma}{\sqrt{n}} = \frac{21}{\sqrt{n}}[/tex]

The approximate standard deviation of the sampling distribution of the mean for all samples of size n is [tex]s = \frac{\sigma}{\sqrt{n}} = \frac{21}{\sqrt{n}}[/tex]


Related Questions

This is a 4th grade level
Ethan puts $1200 into a Certificate of Deposit (CD) account that earns 2.1% interest each year. What will be the interest of the CD account earned after 5 years? Round to the nearest cent (hundredths place).

Answers

Answer:

126

Step-by-step explanation:

1200 x .021=25.20 interest per year

25.20x5=126

assumes no compounding

Anyone know this answer

Answers

Answer:

Step-by-step explanation:

1 is 60 2 i 60 and 3 is 61 ;)

The answer should be 61, goodluck ;)

Your class is selling boxes of flower seeds as a fundraiser. The total profit p depends on the amount x that your class charges for each box of seeds. The equation p= -0.5x2 + 36x - 231 models the profit of the fundraiser. What's the smallest amount, in dollars, that you can charge and make a profit of at least $363?​

Answers

Answer:

The least amount is $75.50

Step-by-step explanation:

Given

[tex]p \to profit[/tex]

[tex]x \to amount[/tex]

[tex]p = -0.5x^2 + 36x - 231[/tex]

Required

The smallest amount to make at least 363

We have:

[tex]p = -0.5x^2 + 36x - 231[/tex]

Rewrite as:

[tex]-0.5x^2 + 36x - 231=p[/tex]

Substitute 363 for p

[tex]-0.5x^2 + 36x - 231 = 363[/tex]

Collect like terms

[tex]-0.5x^2 + 36x - 231 + 363 = 0[/tex]

[tex]-0.5x^2 + 36x + 132 = 0[/tex]

Using quadratic formula, we have:

[tex]x = \frac{-b \± \sqrt{b^2 - 4ac}}{2a}[/tex]

Where:

[tex]a = -0.5; b= 36; c = 132[/tex]

So, we have:

[tex]x = \frac{-36 \± \sqrt{36^2 - 4*-0.5*132}}{2*-0.5}[/tex]

[tex]x = \frac{-36 \± \sqrt{1560}}{-1}[/tex]

[tex]x = \frac{-36 \± 39.50}{-1}[/tex]

Split

[tex]x = \frac{-36 + 39.50}{-1}; x = \frac{-36 - 39.50}{-1}[/tex]

[tex]x = \frac{3.50}{-1}; x = \frac{-75.50}{-1}[/tex]

[tex]x = 75.50[/tex] and [tex]x = -3.50[/tex]

The amount can't be negative.

So:

[tex]x = 75.50[/tex]

Hence, the least amount is $75.50

what is the area of

Answers

Answer:

7 * 9 = 63

63 for when both of the triangles are combined, 31.5 for one triangle.

Rectangle = 18 * 22 = 396

396 + 63

459 cm^2

3 x 5 x 5 x5 x5 x 5 x5 x5

Answers

Answer:

234375

hope this helps

have a good day :)

Step-by-step explanation:

What is the equation of the curve that best fits the data? Round to the nearest hundredths, when appropriate. picture*​

Answers

Answer:

.....

Step-by-step explanation:

Up and down

Answer for brainlest

Answers

Answer:

∠1 = ∠8

Step-by-step explanation:

Because they are ALTERNATE EXTERIOR ANGLE

Answer:

∠1 = ∠8

Step-by-step explanation:

Because alternate exterior angles are equal.

Also there is no angle given so you cant work them out.

simply put:

∠1 = ∠8

∠1 = ∠4

∠3 = ∠2

∠1 = ∠5

∠2 = ∠6

∠2 = ∠7

∠5 = ∠8

∠4 = ∠8

∠7 = ∠6

∠7 = ∠3

Let me know if I missed out on anymore! It was long that's why.

Hope this kind of explained it :)

Suppose customers arrive at a single-server ice cream parlor times 3, 6, 15, and 17. Further suppose that it takes the server 7, 9, 6, and 8 minutes, respectively, to serve the four customers. When does customer 4 leave the shoppe

Answers

9514 1404 393

Answer:

  time 33

Step-by-step explanation:

The first customer arrives at time 3, and is finished being served at time 3+7 = 10.

The second customer arrives at time 6, so waits until time 10 to be served. The second customer is finished being served at time 10+9 = 19.

The third and fourth customers arrive at times 15 and 17. The third customer waits until time 19 to be served, and is finished being served at time 19+6 = 25.

The fourth customer waits until time 25 to be served, and is finished being served at time 25+8 = 33.

The fourth customer leaves at time 33.

A well-conducted opinion poll showed that 48% of voters surveyed favored the reelection of Congressman Porkbarrel. The people who conducted the survey reported that the poll had a margin of error of 3.5%. Which of the following best describes this statement
A. Based on the procedure by which this figure was generated, it is likely that the population proportion is between 44.5% and 51.5%.
B. About 3.5% of the people polled are likely to change their minds about who they will vote foir.
C. Between 44.5% and 51.5% of the voters will vote for Congressman Porkbarrel.
D. About 3.5% ofthe people interviewed refused to answer the question.
E. The probability is .48 that Congressman Porkbarrel will be reelected.

Answers

Answer:

A. Based on the procedure by which this figure was generated, it is likely that the population proportion is between 44.5% and 51.5%.

Step-by-step explanation:

Confidence interval:

We build a confidence interval from a sample proportion, to get an estimate of where the population proportion should likely be.

48% of voters surveyed favored the reelection of Congressman Porkbarrel, with a margin of error of 3.5%.

48 - 3.5 = 44.5%.

48 + 3.5 = 51.5%.

Following the concept of a confidence interval, the population proportion is likely to be between 44.5% and 51.5%, and thus, the correct answer is given by option A.

The area of the rectangle window is4779 cm to the second power if the length of the window is 81 cm what is the width

Answers

9514 1404 393

Answer:

  59 cm

Step-by-step explanation:

The area is the product of length and width. Using the given numbers, we have ...

  A = LW

  4779 cm² = (81 cm)W

  W = (4779 cm²)/(81 cm) = 59 cm

The width of the window is 59 cm.

What is the value of
(x3 x 7y÷)(10.6+5.4)for x=2 and y=6?

Answers

Step-by-step explanation:

Hope you can correct you question

solve the equation

f(x)=13⋅6x for x = 2

Answers

I think the answer is 13 x 6(2) = 156? Sorry if I’m wrong.

Which of the following best represents the slope of the line? A. -3 B. - 1 3 C. 1 3 D. 3

Answers

Pretty sure it’s B. -1/3, hole this helped!

Doug invests in his company's retirement system by depositing $2400 into an account that pays 8% interest compounded quarterly. Approximately how long will Doug need to leave his money in the account for it to have a balance of $25,000? A) 30 years B) 29.6 years C) 29.3 years D) 0.5 year​

Answers

Friends okay we need to be friends now

The probability that Bob and Chris go to the movies is 0.35. The probability that Chris goes to the movies is 0.5. What is the probability that Bob goes to the movies given that Chris goes

Answers

Answer:

[tex]P(B/C)=0.7[/tex]

Step-by-step explanation:

From the question we are told that:

The probability that Bob and Chris go to the movies [tex]P(BnC)= 0.35.[/tex]

The probability that Chris goes to the movies [tex]P(C)= 0.5[/tex]

Generally the equation for the probability that Bob goes to the movies given that Chris goes P(B/C) is mathematically given by

 [tex]P(B/C)=\frac{ P(BnC)}{P(C)}[/tex]

Therefore

 [tex]P(B/C)=\frac{0.35)}{0.5}[/tex]

 [tex]P(B/C)=0.7[/tex]

Five red marbles and 10 blue marbles. what is the probability that she will not pull out a red marble?

Answers

Answer:

5/15 or 1/3

Step-by-step explanation:

does anyone know this?​

Answers

Answer:80^w2−48

Step-by-step explanation:

Answer:

If You Factor it it will be (w+8) (5w2-3)

Step-by-step explanation:

find x and y. For one point extra credit each, give the correct name for point P.

Answers

Answer:

where is the question?

Step-by-step explanation:

Where is the question?

What is the GCF of 11ab + 32ab ?

Answers

The GCF is of 11ab +32ab is 43ab

Given the set of data find the Mean. 4, 5, 6, 12, 12, 12, 14, 16, 22, 23, 28, 28 (round to one decimal place

Answers

Answer:

15.2

Step-by-step explanation:

mean=average

to find the mean, add up all of the numbers and divide by the # of numbers that there are

4+5+6+12+12+12+14+16+22+23+28+28=182

182/12=15.2

Answer:

11.3 to 1DP.

Step-by-step explanation:

The mean = sum of the numbers / 12.

= 136/12

= 11.333

Suppose a fair six sided die has been relabeled so that the 6 is replaced with another 5,i.e., the sides read 1,2,3,4,5,5. If the die is rolled five times, what is the probability that we roll five distinct values

Answers

Answer:

P(rolling five distinct values) = 1/3888

Step-by-step explanation:

We are told that I the fair sided dice, 6 is replaced with 5.

Thus,the numbers are now;

1,2,3,4,5,5.

This means a total of 6 possible numbers appearing.

Now, in these 6 numbers there are only 5 distinct numbers since 5 occurs twice.

P(1) = 1/6

P(2) = 1/6

P(3) = 1/6

P(4) = 1/6

P(5) = 2/6

Thus,probability of rolling 5 distinct values = 1/6 × 1/6 × 1/6 × 1/6 × 2/6 = 1/3888

How do i solve this please help

Answers

Answer:

48

Step-by-step explanation:

138-90(right angled triangle)=48

Need help answering pls

Answers

Answer is C because the angles add up to 90degrees

Hope this helps :D

Answer:

Step-by-step explanation:

angle 2 and angle 3 are complementary angle because their sum is 90 degree as they are perpendicular.

The Pythagorean Identity states that:
(sin x)2 + (cos x)2 = 1
Given cos 6 = 472, find sin .
[?]
sin 0:
O
Simplify the fraction.

Answers

Answer:

[tex]sin(\theta) = \frac{\sqrt{17} }{7}[/tex]

Step-by-step explanation:

We know that:

sin(x)^2 + cos(x)^2 = 1

And we know that:

[tex]cos(\theta) = \frac{4\sqrt{2}}{7} }[/tex]

We want to find the value of the sine function evaluated in theta.

If we replace that in the first equation, we get:

[tex]sin(\theta)^2 + cos(\theta)^2 = 1[/tex]

[tex]sin(\theta)^2 + (\frac{4*\sqrt{2} }{7}) ^2 = 1[/tex]

[tex]sin(\theta)^2 + (\frac{4^2*\sqrt{2}^2 }{7^2}) = 1[/tex]

[tex]sin(\theta)^2 + (\frac{16*2 }{49}) = 1[/tex]

Now we can just isolate the sine part of that equation, so we get:

[tex]sin(\theta)^2 = - (\frac{16*2 }{49}) + 1 = \frac{-32}{49} + \frac{49}{49} = \frac{-32 + 49}{49} = \frac{17}{49}[/tex]

[tex]sin(\theta) = \sqrt{\frac{17}{49} } = \frac{\sqrt{17} }{\sqrt{49} } = \frac{\sqrt{17} }{7}[/tex]

(We can't simplify the fraction anymore)

7+2x/3=5
what is x ?

Answers

Answer:

x = -3

Step-by-step explanation:

7 + 2x/3 = 5

7*3 + 2x = 5*3 ( we multiply by 3 to remove the denominator )

21 + 2x = 15

2x = 15 - 21

2x = -6

x = -6/2

x = -3

Answer:

X=4

Step-by-step explanation:

Times both side by 3

then you get 7+2x=15

then minus 7 from both sides

2x=8

divide by 2

x=4

What type of shape is pentagon

Answers

Answer:Polygon

Step-by-step explanation:

Find the value of x that makes m || n

Answers

Answer:

x = 133

Step-by-step explanation:

x + 14 = 147

x (+ 14 - 14) = 147 - 14

x = 133

The answer is x = 133

Twice a number is 14. What is the number

Answers

Answer:

7

Step-by-step explanation:

Divide 14 by 2

Three coffees and two muffins cost a total of 7 dollars. Two coffees and four muffins cost a total of 8 dollars. What is the individual price for a single coffee and a single muffin?

Answers

Answer:

Cost of a coffee = $1.5

Cost of a muffin = $1.25

Step-by-step explanation:

Given:

Cost of 3 coffee and 2 muffins = $7

Cost of 2 coffee and 4 muffins = $8

Find:

Cost of each

Computation:

Assume;

Cost of a coffee = a

Cost of a muffin = b

So,

3a + 2b = 7 .......... Eq1

2a + 4b = 8 .......... Eq2

Eq1 x 2

6a + 4b = 14 ......... Eq3

From Eq3 - Eq2

4a = 6

a = 1.5

Cost of a coffee = $1.5

3a + 2b = 7

3(1.5) + 2b = 7

4.5 + 2b = 7

b = 2.5/2

b = 1.25

Cost of a muffin = $1.25

Simplify (4a to the fifth power b to the sixth power) to the fourth power

Answers

Answer:

(4a^5b^6)^4 = 256a^20b^24

Step-by-step explanation:

The first person that answered is correct just let you know!
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