Question

Observations are taken on sales of a certain mountain bike in 21 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	1,293.9	389.2
FloorSpace	11.088	1.63
Competing Ads	-6.653	3.962
Price	-0.14949	0.08342

  

(b-1)

What is the critical value of Student's t in Appendix D for a two-tailed test at α = 0.01? (Round your answer to 3 decimal places.)

     

t-value =

(b-2)	Choose the correct option.
	Only Price differs significantly from zero. Only CompetingAds differs significantly from zero. Only FloorSpace differs significantly from zero.

Answer 1

for t =coefficient/std error
a)

Predictor	Coefficient	SE	tcalc	p-value
Intercept	1,293.90	389.2	3.325	0.0040
FloorSpace	11.088	1.63	6.802	0.0000
Competing Ads	-6.653	3.962	-1.679	0.1114
Price	-0.14949	0.08342	-1.792	0.0909

b-1)

critical value of Student's t =2.898

b-2)

Only FloorSpace differs significantly from zero.