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8th Grade Math: Unit 3

Last updated 9 months ago
17 questions
Unit 3 – Item 1
Stacey, a student in Mr. Frances’ 8th grade math class, found the line of best fit for a scatterplot to be 𝑦 = 0.5𝑥 + 10. What does the slope represent for the number of hours spent studying, x, and the test score achieved, y, on the final class exam?
1

for every additional hour spent studying, the test score increases by 0.5 points

1

for every additional point on the test, the number of hours spent studying increases by 0.5 hours

1

for every additional hour spent studying, the test score increases by 10 points

1

for every additional point on the test, the number of hours spent studying increases by 10 hours

Unit 3 – Item 2
Jason is a waiter at Red Lobster. He used a scatter plot to compare the tips earned with the hours worked

1

Model a linear equation of the line of best fit for the scatter plot above

1

What does the slope of the line represent in this situation?

Unit 3 – Item 3
The Math Club is planning a bake sale. They want to see if there is a relationship between the number of cupcakes baked and the total amount of money raised. Math Club members surveyed other clubs about their previous bake sales. They recorded the data in the table below.

1

Create a scatterplot to show the relationship between the number of cupcakes baked and the money raised. Then draw a line of best fit through the data points

1

Using your line of best fit, estimate how much money the Math Club could raise by baking 20 cupcakes

1

Unit 3 – Item 4
In a study analyzing the relationship between rainfall and crop yield, a line of best fit is drawn on a scatter plot. If a point representing a year's data falls significantly below the line of best fit, what can be inferred about that year?

Unit 3 – Item 5
A cold front moved across Georgia. It is 64℉ when the temperature begins to drop. The
scatterplot to model the relationship between the temperature and the number of hours since the cold front arrived is below.

1

What does the rate of change represent in this situation?

1

What is the y-intercept for the line of best fit and what does it represent?

1

What equation relates the change in temperature, y, to the number of hours after the cold front arrives, x? (Round to the nearest whole number)

Unit 3 – Item 6
The graph shows the population of Savannah, y, over the course of 10 years, x. The equation of the line of best fit is 𝑦 = 5736.4𝑥 + 282400.

1

Use the equation to predict the number of years it will take for the population to reach 400,000.

1

If the population continues to increase like this, approximately how many people will be in Savannah in 35 years?

Unit 3 – Item 7
Kai maintained lawns the summer before he left for the University of Georgia. He earned $1500. While he did spend some money on college needs, he saved quite a bit to have money to spend while away at college. The following table shows his bank account balance over an 8-week period in the fall semester.

1

Make a scatter plot of Kai’s bank balance data and draw a line that models the trend in the plot

  • Click the graph tab.
  • Click on the graph background to add a point. Drag a point or type in x and y coordinates to edit its position. Click on a point to delete it.
1

Write an equation for the linear model. Use x for weeks and y for the money left. (Round to the nearest tenth)

1

Predict Kai’s bank balance after 10, 15, and 20 weeks