Scatter Plots and Lines of Best Fit

Connie sells hot chocolate at a stand in a park. She records the number of cups of hot chocolate she sells, as well as the average daily low temperature.

Write the equation for the line of best fit using the values generated with technology.

Interpret the slope of the line of best fit in the context.

• The number of hot chocolate cups sold decreases by 1.91278 with every degree increase.

• The number of hot chocolate cups sold increases by 1.91278 with every degree increase.

Describe the strength of the association between temperature and the number of cups of hot chocolate Connie sells

• Weak

• Negative, strong

• Positive, strong

• Negative,moderate

Suppose Connie knows that tomorrow’s temperature is predicted to be 40℉. Based on the line of best fit, how many cups of hot chocolate should she anticipate selling?

• 90

• 95

• 99

• 87

A few weeks ago, Connie sold 120 cups of hot chocolate. Based on the line of best fit, what was the average temperature that day?

• 37 F

• 0 F

• 53 F

• 29 F

A scatter plot created with technology generated the following values.

Describe the strength of the linear association for this data.

• Strong Positive

• Moderate Positive

• Weak

• Strong Negative

Use this data to write the equation of the line of best fit in slope-intercept form

Use the line of best fit to predict a value for y if the value of x is 18.

• 21

• 20

• 16

• 18

Connie sells hot chocolate at a stand in a park.

She records the number of cups of hot chocolate she sells, as well as the average daily low temperature.

Interpret the y-intercept.

• When the temperature is -0.895 degrees, Conne will sell 178 cups.

• When the temperature is 0 degrees, Connie will sell 176 cups of hot chocolate.

• When the temperature is 49 degrees, Connie will not sell any hot chocolate.

• The y-intercept cannot be interpreted from this data.