# M:C:MC:16

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Learn more about Problem Solving and Data Analysis.

The scatterplot above shows counts of Florida manatees, a type of sea mammal, from 1991 to 2011. Based on the line of best fit to the data shown, which of the following values is closest to the average yearly increase in the number of manatees?

### Select an Answer

0.75

75

150

750

### View Correct Answer

Choice C is correct. The slope of the line of best fit is the value of the average increase in manatees per year. Using approximate values found along the line of best fit (1,200 manatees in 1991 and 4,200 manatees in 2011), the approximate slope can be calculated as

Choice A is not the correct answer. This value may result from disregarding the actual scale when approximating the slope and interpreting the scale as if each square represents one unit.

Choice B is not the correct answer. This value may result from disregarding the actual scale when approximating the slope, and interpreting the scale as if each square along the *x*-axis represents one year and each tick mark along the *y*-axis represents 100 manatees.

Choice D is not the correct answer. This value may result from disregarding the actual scale along the *x*-axis when approximating the slope and interpreting each square along the *x*-axis as one year.

Students must interpret the slope of the line of best fit for the scatterplot as the average increase in the number of manatees per year, while taking the scales of the axes into consideration.