1. The manager of a factory would like to determine the demand for a particular item in order to make a production plan. The demand for the past 15 months is shown below. a) Draw a trend line by eye for these data b) Use a simple regression model to forecast the demand for month 16. c) Calculate the 95% confidence interval around the forecast value. d) Calculate the correlation coefficient and comment on it. Year Demand ( 103 units) 40 45 49 55 62 68 75 85 94 105 11 115 12 124 13 135 14 143 15 154