Question

Refrigerator prices are affected by characteristics such as whether or not the refrigerator is on sale, whether or not it is listed as a Sub-Zero brand, the number of doors (one door or two doors), and the placement of the freezer compartment (top, side, or bottom). The table below shows the regression output from a regression model using the natural log of price as the dependent variable. The model was developed by the Bureau of Labor Statistics.

Variable

Coefficient

Standard Error

t Statistic

Intercept

5.6900

0.12792

44.48

Sale price

−0.0738

0.0286

−2.58

Sub-Zero brand

1.1370

0.1498

7.59

Total capacity (in cubic ft)

0.07473

0.00474

15.76

Two-door, freezer on bottom

0.04278

0.08903

0.48

Two-door, side freezer

Base

Two-door, freezer on top

−0.3046

0.03636

−8.38

One door with freezer

−0.7154

0.1319

−5.42

One door, no freezer

−0.9196

0.1391

−6.61

1) Find the p-value for each coefficient, using 302 degrees of freedom. Using an α = .10, which predictor variable(s) are not significant predictors? (Leave no cells blank - be certain to enter "0" wherever required. Round your answers to 4 decimal places.)

	p-value
SalePrice
Sub-Zero
Capacity
2DoorFzBot
2DoorFzTop
1DoorFz
1DoorNoFz

2) By how much does the natural log of refrigerator price decrease from a two-door, side freezer modelto a two-door, top freezer model? (Round your answer to 4 decimal places.)

The natural log of the price decreases by             

Answer 1

1) Find the p-value for each coefficient, using 302 degrees of freedom. Using an α= .10, which predictor variable(s) are not significant predictors?

Variable	Coefifcient	Standard Error	t statistic	p - value	Significant
Sale price	−0.0738	0.0286	-2.58	0.01035238	Yes
Sub-Zero brand	1.137	0.1498	7.59	4.0073E-13	Yes
Total capacity (in cubic ft)	0.07473	0.00474	15.76	2.9779E-41	Yes
Two-door, freezer on bottom	0.04278	0.08903	0.48	0.63157486	No
Two-door, side freezer	Base
Two-door, freezer on top	−0.3046	0.03636	-8.38	2.0291E-15	Yes
One door with freezer	−0.7154	0.1319	-5.42	1.2207E-07	Yes
One door, no freezer	−0.9196	0.1391	-6.61	1.739E-10	Yes

Question 2

Here the coefficient of  two-door, side freezer model is 0 as it is bas model

Now the coefificent of two-door, top freezer model is -0.3046

so here there is a decrease in natural log of refrigerator price of 0.3046,