Mr. James McWhinney, president of Daniel-James Financial Services, belleves 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. Click here for the Excel Data Fle a. Determine the regression equation. (Negative amounts should be indicated by a minus sign. Do not round intermediate calculations. Round final answers to 2 decimal places.) x=y=sx= b. Determine the estimated sales if 40 contacts are made. (Do not round intermediate caiculations. Round final answer to 2 decimal places.)