Role of retailer interest on shopping behavior. Retail interest is defined by marketers as the level of interest a consumer has in a given retail store. Marketing professors investigated the role of retailer interest in consumers’ shopping behavior (Journal of Retailing, Summer 2006). Using survey data collected for n = 375 consumers, the professors developed an interaction model for y = willingness of the consumer to shop at a retailer’s store in the future (called repatronage intentions) as a function of = consumer satisfaction and = retailer interest. The regression results are shown below.

(a) Is the overall model statistically useful for predicting y? Test using a=0.05

(b )Conduct a test for interaction at a= 0.05.

(c) Use the estimates to sketch the estimated relationship between repatronage intentions (y) and satisfaction when retailer interest is x2=1 (a low value).

(d)Repeat part c when retailer interest is x2= 7(a high value).

(e) Sketch the two lines, parts c and d, on the same graph to illustrate the nature of the interaction.

Short Answer

Expert verified

(a) At 95% significance level, it can be concluded β1 β2β30

(b) Since, β0. Hence it can be concluded with enough evidence that x1and x2 interact in the model. (c) Graph

(d)Graph

(e) Graph

Step by step solution

01

Overall goodness of the fit for the model

H0= β1= β2= β3= 0

Ha= At least one of the parameters is non zero

Here, F test statistic = SSE/ n-(k+1 ) = 226.35

Value of F0.05,371,371 is 1

H0 is rejected if F statistic > F0.05,371,371 . For a= 0.05, since F > F0.05,371,371

Sufficient evidence to reject at 95% confidence interval.

Therefore,β1β2β30

02

Significance ofβ3

H0: β3= 0

Ha: β30

Here, t-test statistic = -0.157/-3.09 =0.0508

Value of t0.05374 is 1.645

H0is rejected if t statistic > t0.05374.

For a= 0.05, since t < t0.05374.

Not sufficient evidence to reject at a 95% confidence interval.

Therefore, β3 0.β

Hence it can be concluded with enough evidence that x1and x2 interact in the model.
03

Graph

Given, E(y) = 0.4226x1 + 0.044x2 - 0.157x1x2for x2=1 .

y= 0.4226x1 + 0.044(1) - 0.157(1)x1for x2 =1 .

y = 0.044 + 0.269x1

for Now to plot this equation, make a table

Y0.0440
X10-0.1635

04

Graph

Given, E(y) = 0.4226x1 + 0.044x2 - 0.157x1x2for x2=7 .

y= 0.4226x1 + 0.044(7) - 0.157(7 )x1for x2 =7 .

y = 0.044 + 0.269x1

Now to plot this equation, make a table

X0.3080
Y00.457

05

Graph

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Question: There are six independent variables, x1, x2, x3, x4, x5, and x6, that might be useful in predicting a response y. A total of n = 50 observations is available, and it is decided to employ stepwise regression to help in selecting the independent variables that appear to be useful. The software fits all possible one-variable models of the form

where xi is the ith independent variable, i = 1, 2, …, 6. The information in the table is provided from the computer printout.

E(Y)=β0+β1xi

a. Which independent variable is declared the best one variable predictor of y? Explain.

b. Would this variable be included in the model at this stage? Explain.

c. Describe the next phase that a stepwise procedure would execute.

Question: Write a second-order model relating the mean of y, E(y), to

a. one quantitative independent variable

b. two quantitative independent variables

c. three quantitative independent variables [Hint: Include allpossible two- way cross-product terms and squared terms.]

Question: Estimating repair and replacement costs of water pipes. Refer to the IHS Journal of Hydraulic Engineering (September, 2012) study of the repair and replacement of water pipes, Exercise 11.21 (p. 655). Recall that a team of civil engineers used regression analysis to model y = the ratio of repair to replacement cost of commercial pipe as a function of x = the diameter (in millimeters) of the pipe. Data for a sample of 13 different pipe sizes are reproduced in the accompanying table. In Exercise 11.21, you fit a straight-line model to the data. Now consider the quadratic model,E(y)=β0+β1x+β2x2. A Minitab printout of the analysis follows (next column).

  1. Give the least squares prediction equation relating ratio of repair to replacement cost (y) to pipe diameter (x).
  2. Conduct a global F-test for the model usingα=0.01. What do you conclude about overall model adequacy?
  3. Evaluate the adjusted coefficient of determination,Ra2, for the model.
  4. Give the null and alternative hypotheses for testing if the rate of increase of ratio (y) with diameter (x) is slower for larger pipe sizes.
  5. Carry out the test, part d, using α=0.01.
  6. Locate, on the printout, a 95% prediction interval for the ratio of repair to replacement cost for a pipe with a diameter of 240 millimeters. Interpret the result.

Forecasting movie revenues with Twitter. Refer to the IEEE International Conference on Web Intelligence and Intelligent Agent Technology (2010) study on using the volume of chatter on Twitter.com to forecast movie box office revenue, Exercise 12.10 (p. 723). The researchers modelled a movie’s opening weekend box office revenue (y) as a function of tweet rate (x1 ) and ratio of positive to negative tweets (x2) using a first-order model.

a) Write the equation of an interaction model for E(y) as a function of x1 and x2 .

b) In terms of theβ in the model, part a, what is the change in revenue (y) for every 1-tweet increase in the tweet rate (x1 ) , holding PN-ratio (x2)constant at a value of 2.5?

c) In terms of the in the model, part a, what is the change in revenue (y) for every 1-tweet increase in the tweet rate (x1 ) , holding PN-ratio (x2)constant at a value of 5.0?

d) In terms of theβ in the model, part a, what is the change in revenue (y) for every 1-unit increase in the PN-ratio (x2) , holding tweet rate (x1 )constant at a value of 100?

e) Give the null hypothesis for testing whether tweet rate (x1 ) and PN-ratio (x2) interact to affect revenue (y).

Question: Failure times of silicon wafer microchips. Refer to the National Semiconductor study of manufactured silicon wafer integrated circuit chips, Exercise 12.63 (p. 749). Recall that the failure times of the microchips (in hours) was determined at different solder temperatures (degrees Celsius). The data are repeated in the table below.

  1. Fit the straight-line modelEy=β0+β1xto the data, where y = failure time and x = solder temperature.

  2. Compute the residual for a microchip manufactured at a temperature of 149°C.

  3. Plot the residuals against solder temperature (x). Do you detect a trend?

  4. In Exercise 12.63c, you determined that failure time (y) and solder temperature (x) were curvilinearly related. Does the residual plot, part c, support this conclusion?

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free