The dean of a college wants to use the mean of a random sample to estimate the average time students take to get from one class to the next. She believes that the population is normally distributed with a standard deviation of 19 minutes. How large a sample should she take to estimate the mean time to within 2 minutes with 98% condence? Sample Size = ' ' preview answc Problem 3. (1 point) The following random sample was selected from a normal distribution: 11111046121710124 (a) Construct a 90% confidence interval for the population mean [4. igu: i (b) Construct a 95% confidence interval for the population mean u. V'SMS ,, i Note: You can earn partial credit on this problem, i . preVIew answt Problem 4. (1 point) A poll is taken in which 326 out of 500 randomly selected voters indicated their preference for a certain candidate. Find a 90% condence interval for p iSpSi