# Sample

Mr. James McWhinney, president of Daniel-James Financial Services, believes there is a relationship between the number of client contacts and the dollar amount of sales. To document this assertion, Mr. McWhinney gathered the following sample information. The X column indicates the number of client contacts last month, and the Y column shows the value of sales ($ thousands)last month for each client sampled.

The table is attached in the file

a. Determine the regression equation.

b. Determine the estimated sales if 40 contacts are made.

c. Determine the standard error of estimate.

d. Suppose a large sample is selected (instead of just 10). About 95 percent of the predictions regarding sales would occur between what two values?

https://brainmass.com/statistics/regression-analysis/15450

#### Solution Preview

Please refer to the attachment.

<br>

<br>a. Determine the regression equation.

<br>

<br>Please refer to the EXCEL for calculation.

<br>The formula of coefficients of Y=a+bX+e is:

<br>b=Σ[(X-Xm)(Y-Ym)] /Σ[(X-Xm)^2] = 5782.80/2759.60=2.096

<br>a=Ym-b*Xm= -10.47

<br>so the regression is

<br>Y= -10.47+2.096 X

<br>

<br>b. ...

#### Solution Summary

Mr. James McWhinney, president of Daniel-James Financial Services, believes there is a relationship between the number of client contacts and the dollar amount of sales. To document this assertion, Mr. McWhinney gathered the following sample information. The X column indicates the number of client contacts last month, and the Y column shows the value of sales ($ thousands)last month for each client sampled.

The table is attached in the file

a. Determine the regression equation.

b. Determine the estimated sales if 40 contacts are made.

c. Determine the standard error of estimate.

d. Suppose a large sample is selected (instead of just 10). About 95 percent of the predictions regarding sales would occur between what two values?