Question

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. (3 points) What is the correlation value “r”?

a. -0.98

b. -0.89

c. 0.89

d. None of the above

2. (3 points) Is the “r” signifcant at alpha = 0.05? (circle one)     Yes     No

3. (4 points) 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. (3 points) 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

5. (4 points) 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. (3 points) 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

Answer 1

Solution :

1)

Option B

2)

Yes

0.89 > 0.707

3)

Option B

4)

y = 19.12 – 1.74 * x

when X = 7

y = 19.12 – 1.74 * 7

y = 6.94

Option C

5)

Option A

6)

y = –12.2 + 2.19(Contacts)

When contacts = 40

y = –12.2 + 2.19 * 40

y = 75.4

Option B