Question

Observations are taken on sales of a certain mountain bike in 30 sporting goods stores. The regression model was Y = total sales (thousands of dollars), X₁ = display floor space (square meters), X₂ = competitors' advertising expenditures (thousands of dollars), X₃ = advertised price (dollars per unit).

(a) Fill in the values in the table given here. (Negative values should be indicated by a minus sign. Leave no cells blank - be certain to enter "0" wherever required. Round your t-values to 3 decimal places and p-values to 4 decimal places.)

Predictor	Coefficient	SE	tcalc	p-value
Intercept	1,238.3	329.7
FloorSpace	11.221	1.99
Competing Ads	-6.731	3.989
Price	-0.14013	0.08743

  
(b-1) What is the critical value of Student's t in Appendix D for a two-tailed test at α = .01? (Round your answer to 3 decimal places.)

t-value =

(b-2) Choose the correct option.

• Only CompetingAds differs significantly from zero.

• Only FloorSpace differs significantly from zero.

• Only Price differs significantly from zero.

Answer 1

a)

Predictor	Coefficient	SE	tcalc	p-value
Intercept	1,238.30	329.7	3.756	0.0009
FloorSpace	11.221	1.99	5.639	0.0000
Competing Ads	-6.731	3.989	-1.687	0.1035
Price	-0.14013	0.08743	-1.603	0.1211

b-1)

critical value of Student's t =2.779

b-2)

Only FloorSpace differs significantly from zero.