1) The heights (in inches) of 20 randomly selected students were recorded below:

67, 63, 68, 68, 70, 62, 65, 64, 68, 65, 60, 64, 61, 65, 67, 72, 67, 62, 64, 66

a) range =

sample standard deviation =

sample variance =

b) Find the value that is one standard deviation above the mean.

c) Find the value that is two standard deviation below the mean.

d) Find the values that are 1.5 times standard deviation above and below the mean.

2) On a baseball team, the ages of each of the players are as follows:

21; 21; 22; 23; 24; 24; 25; 25; 28; 29; 29; 31; 32; 33; 33; 34; 35; 36; 36; 36; 36; 38; 38; 38; 40

a) Range =

sample standard deviation =

Sample variance =

b) Find the values that are two standard deviation above and below the mean. How many values in the dataset are more than two standard deviations above or below the mean?

3) Grades for 20 students are listed below. Find the population standard deviation () and variance. The 20 students are the target group of population.

76, 82, 89, 89, 81, 90, 95, 99, 72, 61, 70, 83, 85, 91, 81, 92, 77, 82, 70, 63

=

2 =