A market researcher is studying online subscription services. She is particularly interested in what variables relate to the number of subscriptions for a particular online service. She is able to obtain the following sample information on 25 on-line subscription services. The following notation is used:

Sub = Number of subscriptions (in thousands)

Web page hits = Average monthly count (in thousands)

Adv = Advertising budget of the service (in $ hundreds)

Price = Average monthly subscription price ($)

Service Sub Web Page Hits Adv Price Service Sub Web Page Hits Adv Price

1 37.95 588.9 13.2 35.1 14 38.39 586.5 15.4 35.5

2 37.66 585.3 13.2 34.7 15 37.29 544.0 11.0 34.9

3 37.55 566.3 19.8 34.8 16 39.15 611.1 24.2 35.0

4 38.78 642.9 17.6 35.1 17 38.29 643.3 17.6 35.3

5 37.67 624.2 17.6 34.6 18 38.09 635.6 19.8 34.8

6 38.23 603.9 15.4 34.8 19 37.83 598.9 15.4 35.1

7 36.90 571.9 11.0 34.7 20 39.37 657.0 22.0 35.3

8 38.28 584.3 28.6 35.3 21 37.81 595.2 15.4 35.1

9 38.95 605.0 28.6 35.1 22 37.42 520.0 19.8 35.1

10 39.27 676.3 17.6 35.6 23 38.83 629.6 22.0 35.3

11 38.30 587.4 17.6 34.9 24 38.33 680.0 24.2 34.7

12 38.84 576.4 22.0 35.4 25 40.24 651.2 33.0 35.8

13 38.14 570.8 17.6 35.0

a. Determine the regression equation.(Negative value should be indicated with a minus sign. Round your answers to 4 decimal places.)

=_______+_______x_{1_________}+x_{2_________}+x₃

b. Conduct a global test of hypothesis to determine whether any of the regression coefficients are not equal to zero.Use = 0.05.(Round your answers to 2 decimal places.)

H₀: ₁= ₂= ₃= 0

H₁: Not all _i's = zero.

Reject H0 if F > ________

F = ________

The null is _______ in favor of the alternative, __________of the independent variables matter(s).

c. Conduct a test for the individual coefficients. Would you consider deleting any coefficients?

All coefficients are __________. Do not delete any.

d. Develop a histogram of the residuals. Do you see any problems with the normality assumption?

The histogram _______ to be normal. There is ________.