Question

AT&T is the second-largest provider of mobile telephony and the largest provider of fixed telephony in the United States, and also provides broadband subscription television services.

The CEO of AT&T wants to know what will affect the Total Monthly Spending at AT&T (y) for a customer. So far, the company has information on customer’s age (X1). We have total 50 observations.

1). Using the knowledge you learned from Chapter 3 to summarize the Total Monthly Spending at AT&T and customer’s age. What are the characteristics of this sample?

2). Determine the simple linear regression equation and interpret the slope

3) What is the goodness of fit of this model? Interpret the statistic.

4). At the 0.05 level, test the slope of the regression model. Write down 4-step. Do you think customer’s age will significantly affect the Total Monthly Spending at AT&T?

5). what is the 95% confidence interval for the slope? How does it tell you about the significance of the slope? Does this conclusion agree with the conclusion from 4)

6). What is the estimated average Total Monthly Spending at AT&T for 25 years old customers?

7). Calculate the prediction interval of the Total Monthly Spending at AT&T for a 25 years old customer (Show your calculation details in Excel). Interpret the results. (α=0.05)

8). Calculate the confidence interval for the mean of the Total Monthly Spending at AT&T for 25 years old customers (Show your calculation details in Excel). Interpret the results. (α=0.05

9). Comparing results from 7) and 8), which one is wider? Why?

10). Calculate SSR, SSE and SST for this model.

Total $'s spent
140
130
45
100
140
140
100
140
160
90
125
130
130
45
75
45
140
140
130
100
140
45
155
140
63
85
240
140
100
140
100
165
240
280
50
100
280
155
45
250
85
85
230
116
125
165
80
240
240
240

Age
35
46
31
50
19
24
25
27
25
50
57
57
33
74
36
60
32
33
32
42
51
34
38
42
74
35
43
63
43
37
20
37
44
52
32
58
29
25
25
28
34
34
38
36
21
28
38
29
34
36

Answer 1

1.

These are continuous bivariate sample.

2.