The quality control manager at a light bulb factory needs to estimate the mean life of a large shipment of light bulbs. The standard deviation is 72 hours. A random sample of 36 light bulbs indicated a sample mean life of 230 hour parts (a) through (d) below. a. Construct a 95% confidence interval estimate for the population mean life of light bulbs in shipment. The 95% confidence interval estimate is from a lower limit of hours to an upper limit of hours. (Round one decimal place as needed.) b. Do you think that the manufacturer has the right to state that the lightbulbs have a mean life of 280 hours? Explain. Based on the sample data, the manufacturer V the right to state that the lightbulbs have a mean life of 280 hours. A mean of 280 hours is V standard errors the sample mean, so it is lightbulbs have a mean life of 280 hours. c. Must you assume that the population light bulb life is normally distributed? Explain. O A. Yes, the sample size is not large enough for the sampling distribution of the mean to be approximately normal by the Central Limit Theorem. O B. Yes, the sample size is too large for the sampling distribution of the mean to be approximately normal by the Central Limit Theorem. OC. No, since a is known and the sample size is large enough, the sampling distribution of the mean is approximately normal by the Central Limit Theorem. O D. No, since a is known, the sampling distribution of the mean does not need to be approximately normally distributed. d. Suppose the standard deviation changes to 51 hours. What are your answers in (a) and (b)? The 95% confidence interval estimate would be from a lower limit of hours to an upper limit of hours. (Round to one decimal place as needed.) Based on the sample data and a standard deviation of 51 hours, the manufacturer V the right to state that the lightbulbs have mean life of 280 hours. A mean of 280 hours is v standard errors mean, so it is that the lightbulbs have a mean life of 280 hours

MATLAB: An Introduction with Applications
6th Edition
ISBN:9781119256830
Author:Amos Gilat
Publisher:Amos Gilat
Chapter1: Starting With Matlab
Section: Chapter Questions
Problem 1P
icon
Related questions
Question
The quality control manager at a light bulb factory needs to estimate the mean life of a large shipment of light bulbs. The standard deviation is 72 hours. A random sample of 36 light bulbs indicated a sample mean life of 230 hours. Complete
parts (a) through (d) below.
a. Construct a 95% confidence interval estimate for the population mean life of light bulbs in this shipment.
The 95% confidence interval estimate is from a lower limit of hours to an upper limit of hours.
(Round to one decimal place as needed.)
b. Do you think that the manufacturer has the right to state that the lightbulbs have a mean life of 280 hours? Explain.
Based on the sample data, the manufacturer
V the right to state that the lightbulbs have a mean life of 280 hours. A mean of 280 hours is
V standard errors
the sample mean, so it is
that the
lightbulbs have a mean life of 280 hours.
c. Must you assume that the population light bulb life is normally distributed? Explain.
O A. Yes, the sample size is not large enough for the sampling distribution of the mean to be approximately normal by the Central Limit Theorem.
O B. Yes, the sample size is too large for the sampling distribution of the mean to be approximately normal by the Central Limit Theorem.
OC. No, since o is known and the sample size is large enough, the sampling distribution of the mean
approximately normal by the Central Limit Theorem.
O D. No, since o is known, the sampling distribution of the mean does not need to be approximately normally distributed.
d. Suppose the standard deviation changes to 51 hours. What are your answers in (a) and (b)?
The 95% confidence interval estimate would be from a lower limit of hours to an upper limit of hours.
(Round to one decimal place as needed.)
Based on the sample data and a standard deviation of 51 hours, the manufacturer
v the right to state that the lightbulbs have a mean life of 280 hours. A mean of 280 hours is
standard errors
the sample
mean, so it is
that the lightbulbs have a mean life of 280 hours.
Transcribed Image Text:The quality control manager at a light bulb factory needs to estimate the mean life of a large shipment of light bulbs. The standard deviation is 72 hours. A random sample of 36 light bulbs indicated a sample mean life of 230 hours. Complete parts (a) through (d) below. a. Construct a 95% confidence interval estimate for the population mean life of light bulbs in this shipment. The 95% confidence interval estimate is from a lower limit of hours to an upper limit of hours. (Round to one decimal place as needed.) b. Do you think that the manufacturer has the right to state that the lightbulbs have a mean life of 280 hours? Explain. Based on the sample data, the manufacturer V the right to state that the lightbulbs have a mean life of 280 hours. A mean of 280 hours is V standard errors the sample mean, so it is that the lightbulbs have a mean life of 280 hours. c. Must you assume that the population light bulb life is normally distributed? Explain. O A. Yes, the sample size is not large enough for the sampling distribution of the mean to be approximately normal by the Central Limit Theorem. O B. Yes, the sample size is too large for the sampling distribution of the mean to be approximately normal by the Central Limit Theorem. OC. No, since o is known and the sample size is large enough, the sampling distribution of the mean approximately normal by the Central Limit Theorem. O D. No, since o is known, the sampling distribution of the mean does not need to be approximately normally distributed. d. Suppose the standard deviation changes to 51 hours. What are your answers in (a) and (b)? The 95% confidence interval estimate would be from a lower limit of hours to an upper limit of hours. (Round to one decimal place as needed.) Based on the sample data and a standard deviation of 51 hours, the manufacturer v the right to state that the lightbulbs have a mean life of 280 hours. A mean of 280 hours is standard errors the sample mean, so it is that the lightbulbs have a mean life of 280 hours.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps

Blurred answer
Similar questions
Recommended textbooks for you
MATLAB: An Introduction with Applications
MATLAB: An Introduction with Applications
Statistics
ISBN:
9781119256830
Author:
Amos Gilat
Publisher:
John Wiley & Sons Inc
Probability and Statistics for Engineering and th…
Probability and Statistics for Engineering and th…
Statistics
ISBN:
9781305251809
Author:
Jay L. Devore
Publisher:
Cengage Learning
Statistics for The Behavioral Sciences (MindTap C…
Statistics for The Behavioral Sciences (MindTap C…
Statistics
ISBN:
9781305504912
Author:
Frederick J Gravetter, Larry B. Wallnau
Publisher:
Cengage Learning
Elementary Statistics: Picturing the World (7th E…
Elementary Statistics: Picturing the World (7th E…
Statistics
ISBN:
9780134683416
Author:
Ron Larson, Betsy Farber
Publisher:
PEARSON
The Basic Practice of Statistics
The Basic Practice of Statistics
Statistics
ISBN:
9781319042578
Author:
David S. Moore, William I. Notz, Michael A. Fligner
Publisher:
W. H. Freeman
Introduction to the Practice of Statistics
Introduction to the Practice of Statistics
Statistics
ISBN:
9781319013387
Author:
David S. Moore, George P. McCabe, Bruce A. Craig
Publisher:
W. H. Freeman