Many supply managers use a monthly reported survey result known as the purchasing managers index (PMI) as a leading indicator to forecast future sales for their businesses. Suppose that the PMI and your business sales data for the last 10 months are as follows: Month 1 2 3 4 5 6 7 8 9 10 PMI 42.1 43.0 41.0 38.2 40.2 44.1 45.8 49.0 48.7 52.0 Sales (1000s) 121 123 125 120 118 118 122 127 135 136 A. Construct a causal regression model using PMI as the causal variable. How well does your model fit the data?