Question

the equation of the line is ( yapprox - 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?
she drew the line of best fit incorrectly.
she used the line of best fit to predict ( y ) for an incorrect value of ( x ).
she forgot the minus sign before the first term on the right side of the equation when she predicted ( y ).
she plugged ( 0.5 ) into the equation for ( y ) instead of ( x ) and actually predicted ( x ) instead of ( y ).

Explanation:

Step1: Substitute \(x = 0.5\) into the equation \(y=-1.02x + 7.09\)

$$
LATEXBLOCK0
$$

Step2: Calculate the value of \(y\)

$$y = 6.58$$

If she got \(y = 7.6\), assume she did \(y=1.02\times0.5+7.09=0.51 + 7.09 = 7.6\). So she forgot the minus sign before the first - term on the right - side of the equation when she predicted \(y\).

Answer:

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