1. A sample of 49 observations is taken from a normal population with a standard deviation of 10. The sample mean is 55.

Determine the 99% confidence interval for the population mean. (Round your answers to 2 decimal places.)

Confidence interval for the population mean is and .

A research firm conducted a survey to determine the mean amount steady smokers spend on cigarettes during a week. They found the distribution of amounts spent per week followed the normal distribution with a population standard deviation of $5. A sample of 64 steady smokers revealed that X=$20.

a.	What is the 95% confidence interval estimate of ? (Round your answers to 3 decimal places.)

Confidence interval is between $ and $ .