The National Collegiate association (NCAA) reported that the mean number of hours spent per week on coaching and recruiting by college football assistant coaches during the season 70. A random sample of 50 assistant coaches showed the sample mean to be 68.6 hours, with a standard deviation of 8.2 hours.
b. Does the 99 percent confidence interval include the valude suggested by the NCAA? Interpret this result.
c. Suppose you decided to switch from 99 to 95 percent confidence interval. Without performing any calculations, will the interval increase, decrease, or stay the same? Which of the values in the formula will change?
a. Using the sample data, construct a 99 percent confidence interval for the population mean.
Since sample size is large, we can use z-distribution.
Z(0.01/2)=Z(0.005)=3.3, so 99% confidence interval ...
This solution provides a z-distribution calculation for finding the confidence interval, as well as discusses what this interval means.