Question

Persons taking a 30-hour review course to prepare for a standardized excam averago a score of 620 on that exam. Persons taking a 70-hour review course average a score of 809. Find a linear function, S(t), which fits this data, and which

expresses score as a function of time. Use this function to predict an average score for persons taking a 42-hour review course. Do not round until the final answer. Then round to the nearest tenth as needed.

Answer 1

S(t) = 4.725t + 478.25

S(t) = 4.725(42)+478.25

S(t) = 676.7

Explanation:

In the question, score is a function of time, that means time is the x-axis, while score is the y-axis.

Order the pairs to get:

(30,620) and (70, 809)

With these values, you use the the equation
`(x2-x1)/(y2-y1)` to get the slope m.

`(70-30)/(809-620) = 4.725`

Use this equation and input any ordered pair to get the final function.

y-y1 = m(x-x1)

y-620 = 4.725x-141.75

y = 4.725x + 478.25

Replace x with t and y with S(t) to fit the x & y axis of the question.