A survey of 34 managers is conducted where each is
asked the amount of their most recent annual raise. The average of the raises was $3,150. The population standard deviation is $650. Conduct a 99% confidence interval for population mean of the manager raises.
Problem: I am having problems with this one.
A random sample of 77 headstones at Ohio cemeteries shows that the average age at death ofCivil War veterans is 48 years
with a sample standard deviation of 9 years. Construct a 90% confidence interval for the population mean of the age of death of Civil War veterans from Ohio.