In: Math
(Answers are given but could you please work through the problem and show me the steps?)
Chapter 8
A local health center noted that in a sample of 400 patients, 80
were referred to them by the local hospital.
| 
 a.  | 
 Provide a 95% confidence interval for all the patients who are referred to the health center by the hospital.  | 
| 
 b.  | 
 What sample size would be required to estimate the proportion of all hospital referrals to the health center with a margin of error of .04 or less at 95% confidence?  | 
| 
 ANSWER:  | 
  
  | 
A simple random sample of 36 items resulted in a sample mean of 40 and a standard deviation of 12. Construct a 95% confidence interval for the population mean.
| 
 ANSWER:  | 
 35.94 to 44.06  | 
Six hundred consumers belonging to the 25-34 age group were
randomly selected in a city and were asked whether they would like
to purchase a domestic or a foreign automobile. Their responses are
given below.
| 
 Preference  | 
 Frequency  | 
| 
 Domestic  | 
 240  | 
| 
 Foreign  | 
 360  | 
Develop a 95% confidence interval for the proportion of all such consumers who prefer to purchase domestic automobiles.
| 
 ANSWER:  | 
 .3608 to .4392  |