A representative of a manufacturing firm wonders whether there is a relationship between a company in his

Question:

A representative of a manufacturing firm wonders whether there is a relationship between a company in his industry's sales and the number of sales representatives on the company staff. He gathers data on 13 manufacturers in his industry which is presented in the following table:

Conduct a simple linear regression between sales and the number of manufacturer's representatives. Solve by excel and Mega Stat. Include "line fit plots" in excel and add "scatterplot" with the Mega Stat solution. Is the regression statistically significant at alpha =.05? How do you know? Be specific.
1. What is the regression equation?
2. For a company with 6 manufacturer's representatives what is the predicted value for sales?
3. What is the 95% prediction interval for the sales of a company having 6 sales representatives? Indicate your conclusion.
4. What percentage of sales is explained by the number of manufacturer's representatives?
Upon reviewing the data plots of this regression analysis as well as a scatter diagram of the data, the manufacturer's representative noticed that the data actually indicated a curvilinear relationship between sales and the number of manufacturer's representatives. It was decided to use the quadratic model for a multiple regression by adding the square of the number of sales representatives to the original data. Conduct this multiple regression using excel and Mega Stat.
1. Is the multiple regression statistically significant at alpha=.05? How do you know? Be specific.
2. What is the multiple regression equation?
3. If the number of sales representatives at a company is 6 what would the predicted sales value? (Note; You should enter 6 and 36 as the typed in values)
4. What would be the 95% prediction interval for sales with a company having 6 sales representatives? State your conclusion.