Question

The equation of the line is y = - 1.02x + 7.09. Using the line, she predicted that when the value of x is 0.5, the value of y will be approximately 7.6. What was her mistake?

A. She drew the line of best fit incorrectly.

B. She used the line of best fit to predict y for an incorrect value of x.

C. She forgot the minus sign before the first term on the right side of the equation when she predicted y.

D. She plugged 0.5 into the equation for y instead of x and actually predicted x instead of y.

Answer 1

The answer is C
If you substitute 0.5 for x in the equation, you get y= 6.58 UNLESS you forget the negative sign in front of the 1.02. Then you'll get 7.6

Answer 2

She forgot the minus sign before the first term on the right side of the equation when she predicted y

Explanation:

The equation of the line is y = - 1.02x + 7.09.

she predicted that when the value of x is 0.5, the value of y will be approximately 7.6

Lets plug in 0.5 for x and check

y = - 1.02x + 7.09

y = - 1.02(0.5) + 7.09

y= 6.58

She forgot the minus sign

1.02(0.5) +7.09 = 7.6

She forgot the minus sign before the first term on the right side of the equation when she predicted y