Studies have shown that the frequency with which shoppers browse Internet retailers is related to the frequency with which they actually purchase products and/or services online. The following data show respondents age and answer to the question "How many minutes do you browse online retailers per year?"

Age (X)

Time (Y)

16

420

17

269

19

315

22

337

22

243

22

459

22

414

28

224

28

381

28

412

28

576

30

333

33

551

34

548

35

626

35

521

35

562

36

699

39

643

39

455

40

666

42

553

43

459

44

525

48

559

50

507

50

612

51

710

52

378

54

566

58

652

59

725

60

695

10)

Use Data > Data Analysis > Correlation to compute the correlation checking the Labels checkbox.

11)

Use the Excel function =CORREL to compute the correlation. If answers for #1 and 2 do not agree, there is an error.

The strength of the correlation motivates further examination.

12)

a) Insert Scatter (X, Y) plot linked to the data on this sheet with Age on the horizontal (X) axis.

b) Add to your chart: the chart name, vertical axis label, and horizontal axis label.

c) Complete the chart by adding Trendline and checking boxes

Read directly from the chart:

13)

a) Intercept =

b) Slope =

c) R² =

Perform Data > Data Analysis > Regression.

14)

Highlight the Y-intercept with yellow. Highlight the X variable in blue. Highlight the R Square in orange

15)

Use Excel to predict the number of minutes spent by a 22-year old shopper. Enter = followed by the regression formula.

Enter the intercept and slope into the formula by clicking on the cells in the regression output with the results.

16)

Is it appropriate to use this data to predict the amount of time that a 9-year-old will be on the Internet?

If yes, what is the amount of time, if no, why?