Please use the following information to solve Q8--Q10: A manager wants to forecast the demand for this week, given the past 5 weeks' sales. What is the slope (b) of the least squares trend line for these data? 28.26 11.5 27.6 20 13.5 Using the information in Q8, what is the Y-intercept (a) of the least squares trend line for these data? 55.85 123.6 115.5 120 117.3 Using the information in Q8, what is this week's forecast using the least squares trend line for these data? 289.2 253.67 201 235.5 186.3