5. A company of 450 factories. Management is interested in average break downs (X) of production lines across all 450 factories per month because of the high cost of breakdowns. From historical data it was found that there was a mean of 120 breakdowns across all factories with a variance of 20. It was also found that about 20% of the factories had no break downs. Answer the following questions. 5.1. What does "a mean of 120 break downs" mean? 5.2. Give the standard deviation of the population. 5.3. Give the variance of the population proportions of the breakdowns. 6. Refer to Question 5. 6.1 With a month's worth of data, a simple random sample, without replacement, of 60 factories was drawn and the following result was determined: X = 100. Explain this in words and in detail. 6.2. Find the standard error of the number of breakdowns per month from the sample and interpret it. 6.3. Find the standard error of the proportion of breakdowns per month from the sample.
5. A company of 450 factories. Management is interested in average break downs (X) of production lines across all 450 factories per month because of the high cost of breakdowns. From historical data it was found that there was a mean of 120 breakdowns across all factories with a variance of 20. It was also found that about 20% of the factories had no break downs. Answer the following questions. 5.1. What does "a mean of 120 break downs" mean? 5.2. Give the standard deviation of the population. 5.3. Give the variance of the population proportions of the breakdowns. 6. Refer to Question 5. 6.1 With a month's worth of data, a simple random sample, without replacement, of 60 factories was drawn and the following result was determined: X = 100. Explain this in words and in detail. 6.2. Find the standard error of the number of breakdowns per month from the sample and interpret it. 6.3. Find the standard error of the proportion of breakdowns per month from the sample.
MATLAB: An Introduction with Applications
6th Edition
ISBN:9781119256830
Author:Amos Gilat
Publisher:Amos Gilat
Chapter1: Starting With Matlab
Section: Chapter Questions
Problem 1P
Related questions
Question
Question 6

Transcribed Image Text:5. A company of 450 factories. Management is interested in average break downs (X) of production
lines across all 450 factories per month because of the high cost of breakdowns. From historical
data it was found that there was a mean of 120 breakdowns across all factories with a variance of
20. It was also found that about 20% of the factories had no break downs.
Answer the following questions.
5.1. What does "a mean of 120 break downs" mean?
5.2. Give the standard deviation of the population.
5.3. Give the variance of the population proportions of the breakdowns.
6. Refer to Question 5.
6.1 With a month's worth of data, a simple random sample, without replacement, of 60 factories
was drawn and the following result was determined:
X = 100.
Explain this in words and in detail.
6.2. Find the standard error of the number of breakdowns per month from the sample and interpret
6.3. Find the standard error of the proportion of breakdowns per month from the sample.
7. Rice Exercise Chapter 7 No 4
4. Two populations are surveyed with simple random samples. A sample of size #₁
is used for population I, which has a population standard deviation o, a sample of
size n. = 2n1 is used for population II, which has a population standard deviation
0₂201. Ignoring finite population corrections, in which of the two samples
would you expect the estimate of the population mean to be more accurate?
Motivate by showing the calculations involved.
8. Rice Chapter 7 no 7
7. Suppose that a simple random sample is used to estimate the proportion of families
in a certain area that are living below the poverty level. If this proportion is roughly
.15, what sample size is necessary so that the standard error of the estimate is .02?
The End
Expert Solution

This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
Step by step
Solved in 2 steps

Recommended textbooks for you

MATLAB: An Introduction with Applications
Statistics
ISBN:
9781119256830
Author:
Amos Gilat
Publisher:
John Wiley & Sons Inc

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
ISBN:
9781305504912
Author:
Frederick J Gravetter, Larry B. Wallnau
Publisher:
Cengage Learning

MATLAB: An Introduction with Applications
Statistics
ISBN:
9781119256830
Author:
Amos Gilat
Publisher:
John Wiley & Sons Inc

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
ISBN:
9781305504912
Author:
Frederick J Gravetter, Larry B. Wallnau
Publisher:
Cengage Learning

Elementary Statistics: Picturing the World (7th E…
Statistics
ISBN:
9780134683416
Author:
Ron Larson, Betsy Farber
Publisher:
PEARSON

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
Statistics
ISBN:
9781319013387
Author:
David S. Moore, George P. McCabe, Bruce A. Craig
Publisher:
W. H. Freeman