1-What is the highest relative score of the three scores below? Use the Z value to answer.

a) a score of 145 with a mean of 138 and a standard deviation of 35

b) a score of 92 on a test with a mean of 88 and a standard deviation of 16

c) a score of 19 on a test with a mean of 15 and a standard deviation of 6

2-In a time study conducted in a manufacturing plant, the time to do a specified operation was measured for each of the 40 workers. The mean and standard deviation were found to be 12.9 and 1.8, respectively. Describe the sample data using the empirical rule (Mendenhall et al., 2015).

3-The mean and variance of a sample of 25 data are 85 and 100, respectively. Use Chebyshev's theorem to describe the distribution of the data

4-The data below are the weights (in pounds) of 15 packages of ground beef in Supermax supermarket refrigerators: 1.28, .90, 1.29, 1.15, .93, 1.18, .89, 1.12, 2.33, 1.94, 2.14, 2.6, 1.11, 1.9, 1.2 (Mendenhall et al., 2015).

a) Construct a stem-and-leaf plot to show the distribution of these weights.

b) Find the mean and standard deviation of the data set.

c) Find the percentage of measurements in the intervals of the empirical rule.