In: Statistics and Probability
Use the following dataset for the next four questions:
X: 5 3 6 3 4 4 6 8
Y: 13 15 7 12 13 11 9 5
1. What is the correlation value “r”?
a. -0.98
b. -0.89
c. 0.89
d. None of the above
2. Is the “r” signifcant at alpha = 0.05? (circle one) Yes No
3. Identify the regression equation below (note: Y is the dependent variable):
a. Y = 19.12 + 1.74(X)
b. Y = 19.12 – 1.74(X)
c. Y = -4.802 – 1.74(X)
d. None of the above
4. Calculate the value of Y when X is 7:
a. 9.64
b. 4.96
c. 6.94
d. None of the above
Mr. James McWhinney, president of Daniel-James Financial Services, believes there is a relationship between the number of client contacts and the dollar amount of sales. To document this assertion, Mr. McWhinney gathered the following sample information. The X column indicates the number of client contacts last month, and the Y column shows the value of sales (in thousands $) last month for each client sampled.
Number of Contacts (X) |
Sales (in thousands $) Y |
14 |
24 |
12 |
14 |
20 |
28 |
16 |
30 |
46 |
80 |
23 |
30 |
48 |
90 |
50 |
85 |
55 |
120 |
50 |
110 |
Identify the regression equation below :
a. Sales = –12.2 + 2.19(Contacts)
b. Sales = 2.19 – 12.2(Contacts)
c. Sales = 6.56 + 0.176(Contacts)
d. None of the above
6. Calculate the estimated sales (in thousands) if 40 contacts are made: ______________
a. Approximately 57
b. Approximately 75
c. Approximately 85
d. None of the above