Description
Please work on chapter 8 problems: 8.1, 8.11, 8.23, 8.29, and 8.41
“8.1 If X?=85, s=8, and n=64, construct a 95% confidence interval estimate for the population mean, ?.
“8.11 If X?=75, S=24, and n=36, and assuming that the population is normally distributed, construct a 95% confidence interval estimate for the population mean, ”
“8.23 A manufacturing company produces electric insulators. You define the variable of interest as the strength of the insulators. If the insulators break when in use, a short circuit is likely. To test the strength of the insulators, you carry out destructive testing to determine how much force is required to break the insulators. You measure force by observing how many pounds are applied to the insulator before it breaks. You collect the force data for 30 insulators selected for the experiment and organize and store these data in Force:
1,870
1,728
1,656
1,610
1,634
1,784
1,522
1,696
1,592
1,662
1,866
1,764
1,734
1,662
1,734
1,774
1,550
1,756
1,762
1,866
1,820
1,744
1,788
1,688
1,810
1,752
1,680
1,810
1,652
1,736
Construct a 95% confidence interval estimate for the population mean force.
What assumption must you make about the population distribution in order to construct the confidence interval estimate in (a)?
Do you think that the assumption needed in order to construct the confidence interval estimate in (a) is valid? Explain.”
“8.29 In a survey of 529 travelers, 386 said that location was very important and 323 said that room quality was very important in choosing a hotel. (Source: C. Jones, ?Top Reason for Picking a Hotel? It?s Where It?s At,? USA Today, April 28, 2014, p. 3B.)
Construct a 95% confidence interval estimate for the population proportion of travelers who said that location was very important for choosing a hotel.
Construct a 95% confidence interval estimate for the population proportion of travelers who said that room quality was very important in choosing a hotel.
Write a short summary of the information derived from (a) and (b).”
“8.41 If the inspection division of a county weights and measures department wants to estimate the mean amount of soft-drink fill in 2-liter bottles to within ?0.01 liter with 95% confidence and also assumes that the standard deviation is 0.05 liter, what sample size is needed?”
Answeres wanted using PHstat
