Question

amara always charges the battery of her motorized wheelchair overnight. at the end of each day, she records the distance she traveled and the remaining charge on the battery. the scatter plot shows the data.

the equation of the line of fit is $y = -3.8x + 100$.
what does the $y$-intercept tell you?

• the remaining charge decreases by 100% each day.
• when amara travels 100 miles, the remaining charge is 0%.
• if amara does not use the wheelchair, the remaining charge is 100%.

Explanation:

In the linear equation $y = mx + b$, the $y$-intercept $b$ is the value of $y$ when $x=0$. Here, $x$ is distance traveled (miles) and $y$ is remaining charge (%). When $x=0$, $y=-3.8(0)+100=100$, meaning no travel leaves 100% charge.

Answer:

If Amara does not use the wheelchair, the remaining charge is 100%.