A local garden shop selected a random sample of 20 weeks and recorded both the price and the the number of weed-eaters sold for each week. The summary statistics are: Price: X = 35, sx = 3.4156 Units sold: y = 4.2857, sy = 2.6904 The correlation between Price and Units sold was r=-0.925 

a) What is the equation of the least-squares estimated regression line?

b) What is the coefficient of determination? 

c) How many weed-eaters can the garden shop expect to sell (on average) if they set the price at $33?