Question [1]: : Based on a survey of 225 employed persons in Ramallah, the mean and variance of the commuting distances between home and the principal place of business are found to be 8 and 9 kilometers, respectively. Determine a 95% confidence interval for the mean commuting distance for the population of all employed persons in Ramallah.

Question [2]: A manager at a power company monitored the employee time required to process high efficiency lamp bulb rebates. A random sample of 49 applications gave a sample mean time of 4.0minutes and a standard deviation of1.0 minute.

Construct a point estimate for thepopulation mean time to process mean ,and give its 80%error margin.