Question

Show computations and steps or you will not receive full credit for correct answers nor partial credit for knowing how to do part of the problem or for knowing what to do despite computational errors.

For a research project, a team of students attended a political speech given by a green party candidate and kept track of how many times a sample of people checked their watches during the speech. Below are the number of times each person checked their watch during the speech (20 people were observed).

8 14 23 5 16 12 6 20 5 10

4 6 9 27 14 11 16 7 24 8

Using these scores, complete the following questions:

a. Calculate the sum of squares (SS), using the computational formula for this data. (3 Points)

b. Calculate the sample variance (s2). (2 Points)

c) Calculate the sample standard deviation (s). (2 Points)

Answer 1

Using the computational formula for the given data:

8, 14, 23, 5, 16, 12, 6, 20, 5, 10, 4, 6, 9, 27, 14, 11, 16, 7, 24, 8

a) The sum of squares is calculated as:

Thus the sample mean is calculated as:

Mean = (8 + 14 + 23 + 5 + 16 + 12 + 6 + 20 + 5 + 10 + 4 + 6 + 9 + 27 + 14 + 11 + 16 + 7 + 24 + 8)/20
= 245/20
Mean = 12.25

so, the sum of squares is calculated as:

b) The sample variance is calculated as:

So, the varince is calculated as:

c) And the sample standard devaition is computed as: