Analyzing Scatterplots and Lines of Best Fit

Suppose data related to the AVERAGE Temperature outside (T) and the number of winter Coats (C) sold at a store is collected and graphed.

The LINE OF BEST FIT has the equation C = -3T + 150.

Use this equation to predict the number of coats sold when the average temperature outside is 20°.

• 40

• 75

• 90

• 115

Suppose a LINE OF BEST FIT passes through the points (6, 34) and (8, 50). The EQUATION of this line is . . .? (hint: find the slope and the equation in point-slope form. THEN put it into slope-intercept form)

• y = 8x – 5

• y = 2x

• y = 2x + 7

• y = 8x – 14

In the scatter plot, does the image shows a "Line of Best Fit"?

• Yes

• No

Tags

CCSS.8.EE.B.5

In the scatter plot, does the image shows a "Line of Best Fit"?

• Yes

• No

Tags

CCSS.8.EE.B.5

The scatterplot shows data collected from 9 people about how much money they earned based on the hours they worked. Use 2 points on the line of best fit and find the slope.

Tags

CCSS.8.EE.B.5

Using your slope from the previous question, give the equation for the line of best fit in point-slope form (choose 1 of the 2 points you used to find the slope)

The scatter plot shows the relationship between the number of chapters and the total number of pages for several books. Use the trend line to predict how many chapters would be in a book with 180 pages.

• 12 chapters

• 15 chapters

• 18 chapters

• 21 chapters

What is the best prediction for the number of candies in the jar when 30 students visit her?

• 90

• 180

• 135

• 150

Suppose a LINE OF BEST FIT passes through the points (4, 8) and (6, 2). The SLOPE of this line is . . .?

• -3

• -6

• 4

• 2

Tags

CCSS.8.EE.B.5

The Y-INTERCEPT of this line is . . .? (hint: find the equation in point-slope form first and then put it into slope-intercept form)

• 11

• 4

• 9

• 20

Tags

CCSS.8.EE.B.6

CCSS.8.F.A.3