1) The new mini-laptop computers can deliver as much computing power as machines several times their size, but they weigh in at less than 3 lb. How large a sample would be needed to estimate the population mean weight if the maximum error of estimate is to be 0.44 of 1 standard deviation with 98% confidence? (Round you answer up to the nearest whole number.)

2)How large a sample should be taken if the population mean is to be estimated with 99% confidence to within $80? The population has a standard deviation of $904. (Round your answer up to the next whole number.)

3)A sample of58night-school students' ages is obtained in order to estimate the mean age of night-school students.x=24.5years. The population variance is20.

(a) Give a point estimate for. (Give your answer correct to one decimal place.) (b) Find the 95% confidence interval for. (Give your answer correct to two decimal places.)

Lower Limit
Upper Limit

(c) Find the 99% confidence interval for. (Give your answer correct to two decimal places.)

Lower Limit
Upper Limit