Question

john has a part - time job at an ice skating rink selling hot cocoa. he decided to plot the number of hot cocoas he sold relative to the days high temperature and then draw the line of best fit. based on the line of best fit, how many hot cocoas would you predict john to sell if the days high temperature were 30°f? answer attempt 1 out of 2 hot cocoas submit answer

Explanation:

Step1: Find the slope of the line of best fit

Use the formula for slope \(m=\frac{y_2 - y_1}{x_2 - x_1}\). Let \((x_1,y_1)=(0,101)\) and \((x_2,y_2)=(10,93)\).
\(m=\frac{93 - 101}{10-0}=\frac{-8}{10}=- 0.8\)

Step2: Write the equation of the line

The equation of a line in slope - intercept form is \(y = mx + b\). Since \(b = 101\) (when \(x = 0,y=101\)) and \(m=-0.8\), the equation is \(y=-0.8x + 101\)

Step3: Predict the number of hot - cocoas for \(x = 30\)

Substitute \(x = 30\) into the equation \(y=-0.8x + 101\).
\(y=-0.8\times30+101\)
\(y=-24 + 101\)
\(y = 77\)

Answer:

\(77\)