Question

students at forestdale middle school can deposit money in accounts to use to buy lunch. this scatter plot shows the balances of several lunch accounts during the first month of the school year. the scatter plot also shows the line of best fit. lunch account balances the equation for the line of best fit is y = -8.12x + 43.4. according to the equation, which of these statements is true? students tend to spend between $8 and $9 each day. students typically started the school year with about $43 in their accounts.

Explanation:

Step1: Analyze the slope - intercept form

The equation of the line is $y=-8.12x + 43.4$, which is in the form $y = mx + b$, where $m$ is the slope and $b$ is the y - intercept.

Step2: Interpret the slope

The slope $m=-8.12$. Since $x$ represents weeks since school started, it means the balance decreases by about $8.12$ per week. It is not per day.

Step3: Interpret the y - intercept

The y - intercept $b = 43.4$. When $x = 0$ (at the start of the school year), $y=43.4$. So students typically started the school year with about $43$ in their accounts.

Answer:

Students typically started the school year with about $43$ in their accounts.