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3. A baker wants to estimate the average baking time for a new batch of chocolate chip cookies. She knows from experience that baking times are normally distributed with a population standard deviation $\sigma$ = 3 minutes. A random sample of 12 cookies resulted in the following baking times (in minutes): 10 12 9 14 11 8 13 10 15 12 8 11 a. Calculate the sample mean for the baking times. (3 points) b. What confidence level would you recommend for this scenario? Explain. (3 points) c. Find the critical value for a 99% confidence level. (3 points) d. Calculate the margin of error for the confidence interval. (4 points) e. Construct the 99% confidence interval for the average baking time of all cookies using this recipe. (4 points) f. Interpret the confidence interval you found in part (e) in the context of the problem. (3 points)

          3. A baker wants to estimate the average baking time for a new batch of chocolate chip cookies.
She knows from experience that baking times are normally distributed with a population
standard deviation $\sigma$ = 3 minutes. A random sample of 12 cookies resulted in the following
baking times (in minutes):
10
12
9
14
11
8
13
10
15
12
8
11
a. Calculate the sample mean for the baking times. (3 points)
b. What confidence level would you recommend for this scenario? Explain. (3 points)
c. Find the critical value for a 99% confidence level. (3 points)
d. Calculate the margin of error for the confidence interval. (4 points)
e. Construct the 99% confidence interval for the average baking time of all cookies using
this recipe. (4 points)
f. Interpret the confidence interval you found in part (e) in the context of the problem.
(3 points)

Show more…

3. A baker wants to estimate the average baking time for a new batch of chocolate chip cookies.
She knows from experience that baking times are normally distributed with a population
standard deviation σ = 3 minutes. A random sample of 12 cookies resulted in the following
baking times (in minutes):
10
12
9
14
11
8
13
10
15
12
8
11
a. Calculate the sample mean for the baking times. (3 points)
b. What confidence level would you recommend for this scenario? Explain. (3 points)
c. Find the critical value for a 99% confidence level. (3 points)
d. Calculate the margin of error for the confidence interval. (4 points)
e. Construct the 99% confidence interval for the average baking time of all cookies using
this recipe. (4 points)
f. Interpret the confidence interval you found in part (e) in the context of the problem.
(3 points)

Added by Diana H.

Elementary Statistics a Step by Step Approach

Allan G. Bluman 9th Edition

Instant Answer

Solved by Expert Jerelyn Nevil

09/08/2023

Step 1

To find the sample mean, we sum up all the baking times and divide by the number of cookies in the sample. Sample mean = (10 + 12 + 9 + 14 + 11 + 8 + 13 + 10 + 15 + 12 + 8 + 11) / 12 Sample mean = 133 / 12 Sample mean = 11.0833 minutes (approximately) Show more…

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need calculator calculations A baker wants to estimate the average baking time for a new batch of chocolate chip cookies. She knows from experience that baking times are normally distributed with a population standard deviation sigma =3 minutes. A random sample of 12 cookies resulted in the following baking times (in minutes): 10 12 9 14 11 8 13 10 15 12 8 11 a. Calculate the sample mean for the baking times. (3 points) b. What confidence level would you recommend for this scenario? Explain. (3 points) c. Find the critical value for a 99% confidence level. (3 points) d. Calculate the margin of error for the confidence interval. (4 points) e. Construct the 99% confidence interval for the average baking time of all cookies using this recipe. (4 points) f. Interpret the confidence interval you found in part (e) in the context of the problem. (3 points) A baker wants to estimate the average baking time for a new batch of chocolate chip cookies She knows from experience that baking times are normally distributed with a population standard deviation = 3 minutes. A random sample of 12 cookies resulted in the following baking times(in minutes): 10 12 9 14 11 8 13 10 15 12 8 11 a. Calculate the sample mean for the baking times.(3 points b.What confidence level would you recommend for this scenario? Explain.(3 points) c.Find the critical value for a 99% confidence level.(3 points d.Calculate the margin of error for the confidence interval.4 points e. Construct the 99% confidence interval for the average baking time of all cookies using this recipe. (4 points) F. Interpret the confidence interval vou found in part(e)in the context of the problem (3 points)

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Transcript

00:01 Okay, so i see that you need help with this question.

00:02 So it's a sample size of 12, a mean of 48, and a standard deviation of 5.

00:08 Find the margin of error at an 80 % confidence interval.

00:13 So first thing you're going to do is 1 minus 0 .8, which is 0 .2.

00:19 1 minus 0 .2 divided by 2, and that is 0 .9.

00:27 And then you have t0 .9, a degrees of freedom of 11.

00:32 So that's 1 .36.

00:34 So that number is very important.

00:37 So then you're going to take 48 plus or minus 1 .36 times 5 over the square root of 12, 48 plus or minus 1 .36 times 1 .44, and then 48 plus or minus 1 .97.

00:55 And then we have a confidence interval of 46 .03 comma 49 .97.

01:05 Then it says find the critical value that corresponds to the confidence interval of 99%, 99 .9 % i should say.

01:24 So you're going to do 1 minus 0 .999 equals 0 .001.

01:32 1 minus 0 .001 divided by 2, and that is 0 .9995.

01:38 So that's a critical value.

01:45 Karen wants to advertise how many chocolate chips are in each.

01:50 Big chocolate chip at her bakery.

01:53 She randomly selects 48 cookies and finds the number of chocolate chips per cookie in the sample has a mean of 18 .4 and a standard deviation of 16.

02:06 And wants to know the 95 % confidence interval.

02:14 So you have an average of 48, a mean of 18 .4, a standard deviation of 16.

02:37 So then that's going to be 0 .95.

02:43 I'm sorry, 0 .999...

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