Using Linear Models to Make Predictions

The grade of a hill is its steepness represented as a percent. Jin tracks his walking speed up different hills. What does the rate of change, or slope, represent in this situation?

• The rate represents an increase in speed for each 1% grade increase.

• The rate represents a decrease in speed for each 1% grade decrease.

• The rate represents a decrease in speed for each 1% grade increase.

• The rate represents no change in speed for each 1% grade decrease.

Which statement is true about using scatter plots to make predictions?

• You cannot make predictions by visually using the trend line.

• Any two points can be used to draw a trend line.

• All you need is the slope of the trend line.

• You can use the equation of a trend line to find the y-value of a given x-value.

The scatter plot shows the time spent studying compared to test scores for Mr. Stone’s eighth-grade class. Predict the score that a student would earn if she studied for 7 hours. Round your answer to the nearest whole number.

• 75

• 79

• 80

• 85

The equation below represents an elevator's height after an amount of seconds. Using this equation, what should the height of the elevator be after 14 seconds?
h(s) = -3.8s + 290

• 80
• 236.8
• -80
• 72.6

The amount of water in the bucket ( in pints) can be modeled by the equation V(n) = 2n + 7 where n is the number of pitchers used to put water in the bucket.  If the bucket contains 29 pints of water, how many pitchers of water were used to fill it?

• 11
• 65
• 9
• 18

R(n)=125 + 80n models the amount of money R(n) in the register after selling n tickets. How much money is in the register before selling any tickets? 

• $125
• $80
• $205
• $45

A driving range charges $4 to rent a golf club plus $2.75 for every bucket of golf balls you hit. Write an equation that shows the total cost c of hitting b buckets of golf balls.

• c = 2.75b + 4
• c = 2.75b
• c =  4b- 2.75
• c = 2.75b - 4

Asia is a salesperson for Quark Computer Company. Each month she earns $2500 as well as 1/6 of every sale she makes. How many sales did she make to earn $2700 last month?

• 1150
• 1000
• 1250
• 1200

The value of a particular car model t years after its purchased is given by
V(t) = 25000-3000t
What is the cars value 6 years after it is purchased?

• $6850
• $7000
• $7500
• $8250

The cost of hiring a private tutor is modeled by the function C(n)=32n+20. How much does the tutor charge per hour?

• $32 per hour
• $20 per hour
• $52 per hour
• $12 per hour