A store manager wants to know the demand for a product as a function of the price. The table shows the daily sales y for different prices x of the product.

(a) Find the least squares regression line y = ax + b for the data by solving the system

For a and b. Use a graphing utility to confirm the result.
(b) Use the linear model from part (a) to predict the demand when the price is $1.75.
One way to find the least squares regression line y ax b for a set of points (x1, y1), (x2, y2) . . . (xn, yn) is by solving the system below for a and b.

Price, x Demand, y $1.00 45 $1.20 37 $1.50 23 (3.00b + 3.70a = 105.00 (3.70b + 4.69a = 123.90