Unit 7 and 8 EOC Review

A scientist studied the relationship between the number of trees, x, per acre and the number of birds, y, per acre in a neighborhood. She modeled the relationship with a scatter plot and used the equation y = 4 + 6x for the regression line. What is the meaning of the slope and y-intercept of this regression line?

• The slope is 6. This means that the average number of birds per acre in an area with no trees is 6. The y-intercept is 4. This means that for every 1 additional tree, she can expect an average of 4 additional birds per acre.

• The slope is 4. This means that for every 1 additional tree, she can expect an average of 4 additional birds per acre. The y-intercept is 6. This means that the average number of birds per acre in an area with no trees is 6.

• The slope is 6. This means that for every 1 additional tree, she can expect an average of 6 additional birds per acre. The y-intercept is 4. This means that the average number of birds per acre in an area with no trees is 4.

• The slope is 4. This means that the average number of birds per acre in an area with no trees is 4. The y-intercept is 6. This means that for every 1 additional tree, she can expect an average of 6 additional birds per acre.

Kendra and Theo each collected data on the number of birds they observed at a bird feeder each hour for eight hours. The data Kendra collected are summarized as shown. - The range of Kendra’s data is 6. - The median of Kendra’s data is 7. - The mean of Kendra’s data is 7. The data Theo collected have the same range and the same median as the data Kendra collected, but the mean of Theo’s data is 7.5. The line plot correctly shows six of the eight data points for Theo’s data set. Plot the remaining two data points on the line plot.

• The remaining two data points should be plotted at 10 and 12 on the line plot.

• The remaining two data points should be plotted at 6 and 8 on the line plot.

• The remaining two data points should be plotted at 7 and 13 on the line plot.

• The remaining two data points should be plotted at 5 and 11 on the line plot.

Which set of data points could BEST be modeled by a line of best fit that is a decreasing linear function?

• {(0, 0), (1, 8), (2, 15), (3, 22), (4, 30)}

• {(0, 5), (1, 6), (2, 10), (3, 16), (4, 28)}

• {(0, 50), (1, 42), (2, 33), (3, 25), (4, 16)}

• {(0, 64), (1, 60), (2, 52), (3, 39), (4, 22)}

The numbers of customers that visited a store certain numbers of hours after the store opened at 8 A.M. are shown in the table below: Hours after 8 A.M.: 1, 3, 4, 6, 9 Number of Customers: 2, 15, 18, 13, 0 Which statement BEST describes the data?

• The data can be modeled by a linear function.

• The data can be modeled by a constant function.

• The data can be modeled by a quadratic function.

• The data can be modeled by an exponential function.

Refer to the scatter plot showing the number of customers versus hours after 8 A.M. At what hour after 8 A.M. did the number of customers reach its highest point?

• 2 hours

• 4 hours

• 6 hours

• 8 hours

Triangle ABC has vertices as shown. (A(1,4), B(4,1), C(-3,0)) What is the area of the triangle?

• √72 square units

• 12 square units

• √288 square units

• 24 square units

An equation of line a is y = -1/2x - 2. Which is an equation of the line that is perpendicular to line a and passes through the point (-4, 0)?

• y = -1/2x + 2

• y = -1/2x + 8

• y = 2x - 2

• y = 2x + 8

Look at the square WXYZ on this coordinate plane. Which measure is closest to the perimeter of square WXYZ?

• 20 units

• 44 units

• 32 units

• 40.9 units

According to the table, what is the distance traveled by the car after 3 seconds?

• 108 feet

• 90 feet

• 120 feet

• 75 feet

How many feet does the car travel in the first 2 seconds?

• 48 feet

• 24 feet

• 60 feet

• 36 feet