1. A sample of 10 observations is selected from a normal population for which the population standard deviation is known to be 4. The sample mean is 24.
The 99 percent confidence interval for the population mean is between_______ and______ .
2. The owner of Britten's Egg Farm wants to estimate the mean number of eggs laid per chicken. A sample of 20 chickens shows they laid an average of 20 eggs per month with a standard deviation of 2.96 eggs per month.
The 95 percent confidence interval for the population mean is _________ to ___________
3. A survey is being planned to determine the mean amount of time corporation executives watch television. A pilot survey indicated that the mean time per week is 18 hours, with a standard deviation of 5.0 hours. It is desired to estimate the mean viewing time within one-quarter hour. The 95 percent level of confidence is to be used.
How many executives should be surveyed?