Question

You have been asked to engage in one final project concerning the sales of the Nikon D5 camera. This time you wish to study the nature of the relationship between sales of the camera body and sales of a certain lens that can be used with this body and other Nikon bodies. Specifically, you wish to study whether and to what extent if the sale of Nikon D5 camera bodies explains and predicts the sale of the lens. Data concerning these two variables of interest is collected over a one-year period from a representative sample of stores in the chain of stores that sell both the body and the lens. This data is shown in appendix one. The questions that need to be answered about the results you generate are also shown below. Don’t forget that you need to also provide business implications concerning the overall results of the study concentrating on the results of the inferential portions of the problem as you state and develop your implications. Submit your work to the drop box for assignment five that has been created for this purpose. Reference the usual places in your textbook should you need help using PHStat to accomplish this assignment.

Appendix One:

Data:

                                    Sales of Body                       Sales of Lens                       

                                                155                                         122

                                                101                                         120

                                                157                                         135

                                                180                                         95

                                                150                                         100

                                                201                                         174

                                                99                                         118

                                                137                                         130

                                                155                                         128

                                                165                                         166

                                                152                                         131

                                                127                                         102

                                                217                                         165

                                                186                                         154

                                                176                                         97

                                                123                                         129

                                                109                                         98

                                                90                                         105

                                                176                                         120

                                                129                                         105

k. At the 5% level of significance, is there evidence of a significant linear relationship between the sales of Nikon D5 bodies and the sales of the lens? Be sure that you explain in some manner the criterion or criteria you have used to arrive at your conclusion.

l. Find a 95% confidence interval for the slope of the population regression line. Provide an explanation of the meaning of this interval in the context of the problem. Show how this interval can be used to answer the question posed (at the 5% level of significance) in the previous part of the problem.

Answer 1

The 95% confidence interval does not include the value zero. Hence, the slope has significant effect and does not equal to zero and also this interval can be used to answer the question posed (at the 5% level of significance) in the previous part of the problem.