A regression analysis was conducted to predict the number of items sold based on the number of sales calls. Number of items sold were ranges from 20 to 60 and the number of sales calls ranges from 20 to 170. For the sample data, the fitted regression model is y=19.9632+0.2608x. Estimate the number of items sold when the sales calls were 164. a) 62.7344 b) 60.7344 c) 70.7344 d) 72.7344