Question

Calculating Predictions Using the Regression Equation
A graph has average temperature (degrees Fahrenheit) on the x-axis, from 0 to 60, and total coat sales on the y-axis, from 0 to 100. A trend line goes through points (55, 50) and (65, 40). The regression equation is y = negative 0.96 x + 103.

What is the prediction of the number of coats Clothes-4-You will sell when the outside temperature is 20ºF? Round to the nearest whole number.

1. Substitute 20 for x in the equation.

2. Simplify to find the value for y.


At 20°F, about
coats will be sold at Clothes-4-You.

Answer 1

1. y = -0.96(20) + 103
2. y = -19.2 + 103 = 83.8 ≈ 84

At 20°F, about 84 coats will be sold.