SAT Math Multiple Choice Question 844: Answer and Explanation
Wesley went to an amusement park with his family. He paid for his own admission ticketand all of the rides he rode. The scatterplot shows possible amounts that he couldhave paid. If a line of best fit (not shown) is used to model the data, the equationof the line would be y = 3x + 8. In this scenario, what does 3 represent?
- A. The cost of one ride
- B. The number of rides Wesley rode
- C. The cost of the admission ticket
- D. The number of hours Wesley stayed at the park
Correct Answer: A
Category: Problem Solving and Data Analysis / Scatterplots
Strategic Advice: When a linear equation is written in the form y = mx + b, m is the slope and b is the y-intercept. In a real-world scenario, the y-intercept represents a flat fee or a starting amount, and the slope represents a unit rate.
Getting to the Answer: The 3 in the equation is the coefficient of x, so it is the slope of the line of best fit. This means that the number 3 represents a unit rate. Read the axis labels carefully. The numbers of rides are plotted along the horizontal axis, so x represents the number of rides, which means 3 must be the cost per ride, or the cost of 1 ride, which is (A).