a. Use the data to develop an estimated regression equation that could be used to predict the annual maintenance expense in hundreds of dollars (y) for a given number of hours of weekly usage (x). What is the estimated regression model? (Round your numerical values to four decimal places.) Y-hat____ b. Test whether the regression parameter $ is equal to zero at a 0.05 level of significance. Find the p-value. (Round your answer to four decimal places.) p-value =___ c. Test whether the regression parameter B, is equal to zero at a 0.05 level of significance. (Use the t test.) Find the p-value. (Round your answer to four decimal places.) p-value =___ - How much of the variation in the sample values of annual maintenance expense (in %) does the model you estimated in part (b) explain? (Round your answer to one decimal place.) ___% - If the maintenance contract costs $3,300 per year, would you recommend purchasing it? Why or why not? (Round your answers to two decimal places.) The mean weekly usage in our sample is 25.3 hours per week. The expected expense of a machine being used 25.3 hours per week is $____hundred. Since this expected expense is than the cost of the maintenance contract, the maintenance contract advisable.