1.) A decision maker is interested in estimating the mean of a population based on a random sample. She wants the confidence level to be 95% and the margin of error to be 0.40. She does not know what the population standard deviation is, so she has selected the pilot sample below. Based on this pilot sample, how many more items must be sampled so that the decision maker can make the desired confidence interval estimate?

8.50 4.77 10.98 15.11 14.86

16.98 1.29 9.06 14.23 5.67

7.25 3.26 2.59 6.12 6.96

The decision maker should sample ______ more items to make the desired confidence interval estimate (round up to the nearest whole number)