Question 3-

Use the dependent variable (labeled Y) andoneof the independent variables (labeled X1, X2, and X3) in the data file. Select and use one independent variable throughout this analysis. Use Excel to perform the regression and correlation analysis to answer the following. The week 6 spreadsheet can be helpful in this work.

1. Generate a scatterplot for the specified dependent variable (Y) and the selected independent variable (X), including the graph of the "best fit" line. Interpret.
2. Determine the equation of the "best fit" line, which describes the relationship between the dependent variable and the selected independent variable.
3. Determine the correlation coefficient. Interpret.
4. Determine the coefficient of determination. Interpret.
5. Test the utility of this regression model by completing a hypothesis test of b=0 using =0.10. Interpret results, including the p-value.
6. Based on the findings in steps 1-5, analyze the ability of the independent variable to predict the dependent variable.
7. Compute the confidence interval for b, using a 95% confidence level. Interpret this interval.
8. Compute the 99% confidence interval for the dependent variable, for a selected value of the independent variable. Each student can choose a value to use for the independent variable (use same value in the next step). Interpret this interval.
9. Using the same chosen value for part (8), estimate the 99% prediction interval for the dependent variable. Interpret this interval.
10. What can be said about the value of the dependent variable for values of the independent variable that are outside the range of the sample values? Explain.

Sales (Y) Calls (X1) Time (X2) Years (X3) Type

37 131 16.9 2 GROUP

44 134 19.4 3 GROUP

33 139 19.3 3 GROUP

40 145 14.7 2 GROUP

35 149 15.6 1 GROUP

47 149 15.8 1 GROUP

26 150 14.9 2 GROUP

39 150 15.3 3 GROUP

47 151 16.6 2 GROUP

25 152 15.0 3 GROUP

41 152 14.5 4 GROUP

49 153 19.0 3 GROUP

42 154 14.3 2 GROUP

42 154 15.3 1 GROUP

25 155 17.9 1 GROUP

45 156 13.2 3 GROUP

50 157 15.9 3 GROUP

44 159 14.6 2 GROUP

42 161 13.2 1 GROUP

48 162 14.5 4 GROUP

41 164 17.8 3 GROUP

67 166 18.9 1 GROUP

44 168 12.4 2 GROUP

43 169 14.05 GROUP

22 170 14.3 4 GROUP

46 172 14.7 3 GROUP

43 175 13.6 5 GROUP

49 178 18.3 2 GROUP

44 192 16.7 1 GROUP

25 130 12.8 2 NONE

36 131 11.7 3 NONE

35 131 21.6 1 NONE

36 131 18.5 0 NONE

49 131 14.6 1 NONE

37 132 10.0 3 NONE

38 135 18.5 3 NONE

22 139 16.9 4 NONE

39 140 12.4 0 NONE

42 140 17.5 3 NONE

37 142 13.9 2 NONE

25 143 15.4 1 NONE

50 144 15.8 2 NONE

22 145 19.0 2 NONE

50 148 16.0 0 NONE

67 155 17.9 1 NONE

37 159 18.1 0 NONE

39 160 14.3 4 NONE

45 138 15.3 2 ONLINE

36 140 15.7 1 ONLINE

39 144 17.7 1 ONLINE

41 149 17.3 0 ONLINE

45 149 13.5 1 ONLINE

42 152 14.6 1 ONLINE

44 153 15.3 2 ONLINE

41 155 16.0 2 ONLINE

44 156 20.0 0 ONLINE

40 157 15.4 1 ONLINE

34 158 14.2 3 ONLINE

41 159 18.8 2 ONLINE

43 160 10.9 4 ONLINE

44 160 14.8 2 ONLINE

43 161 17.3 3 ONLINE

46 163 16.6 2 ONLINE

44 165 15.7 3 ONLINE

44 165 12.4 3 ONLINE

48 167 14.8 3 ONLINE

42 168 16.4 0 ONLINE

44 168 11.0 5 ONLINE

41 170 12.3 0 ONLINE

45 170 14.2 1 ONLINE

48 170 17.4 5 ONLINE

46 171 14.9 5 ONLINE

48 171 13.0 5 ONLINE

30 173 17.5 1 ONLINE

43 174 12.7 2 ONLINE

45 174 13.6 2 ONLINE

40 176 12.6 1 ONLINE

21 177 17.0 0 ONLINE

41 178 13.4 2 ONLINE

49 178 15.1 3 ONLINE

49 178 16.4 2 ONLINE

51 178 16.5 1 ONLINE

41 180 14.0 2 ONLINE

42 181 11.5 4 ONLINE

48 182 13.0 2 ONLINE

46 183 15.4 4 ONLINE

46 184 12.7 5 ONLINE

52 184 11.4 4 ONLINE

21 185 18.9 2 ONLINE

47 186 13.5 3 ONLINE

48 186 14.2 1 ONLINE

48 188 13.6 0 ONLINE

48 188 11.3 2 ONLINE

50 189 14.3 1 ONLINE

56 189 15.0 3 ONLINE

40 191 19.0 5 ONLINE

52 193 13.7 5 ONLINE

42 194 13.6 2 ONLINE

41 198 13.2 2 ONLINE

48 201 12.5 1 ONLINE