Problem 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....

Problem

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.