Question

Homework Question #1:

The Following Table shows total annual sales for 10 high-end supermarket stores and the median age of residents of each town where these stores are located. Supermarket executives believe that their store products appeal to a younger generation. (obtain all graphs and calculations from minitab, but provide all manual calculations)

Sales ($M)	5.540	10.700	10.532	5.995	5.090
Median Age	39.5	34.5	30.4	36.2	40.8
Sales ($M)	3.995	2.774	4.828	5.511	4.195
Median Age	41.5	34.7	41.4	38.0	40.0

1. Obtain a scatterplot and examine/describe the general relationship between sales and median age of the town residents
2. Do you think the linear model is appropriate? Explain
3. The marketing manager fit the regression line. What is the equation of that line? Is the regression significant? What is the R-Square value?
4. From a “Regression Analysis” report obtained from minitab, do you have any reservations about the prediction you found in (d)? Explain

Answer 1

c) From the given data,
S.No.   Sales (X)   Median Age (Y)   (Xi-Xbar)^2   (Yi-Ybar)^2   (xi-xbar)(yi-ybar)
1   5.54   39.5     0.141376 3.24   -0.6768
2   10.7   34.5   22.886656 10.24   -15.3088
3   10.532   30.4      21.307456    53.29   -33.6968
4   5.995   36.2   0.006241   2.25   -0.1185
5   5.09   40.8 0.682276    9.61 -2.5606
6   3.995   41.5   3.690241 14.44   -7.2998
7   2.774   34.7   9.872164 9 9.426
8   4.828   41.4 1.183744 13.69 -4.0256
9   5.511   38 0.164025 0.09 -0.1215
10   4.195   40 2.961841    5.29 -3.9583
Total:   59.16   377 62.89602 121.14 -58.3407
Mean(x) = 59.16/10 = 5.916
Mean (y) = 377/10 = 37.7

d) Report from MINITAB is