Problem-Solving and Data AnalysisMediumDifference between two predictions from a fitted line
Problem-Solving and Data Analysis practice question
A line of best fit relating the hours of sunshine x on a day to the number of ice creams y a stall sells has the equation y = 40x + 15. How many more ice creams does the line predict for a day with 8 hours of sunshine than for a day with 3 hours?
Answer: 200
The difference is the slope times the change in x: 40 × (8 − 3) = 200.
Common wrong answers
- If you answered 5
- 5 is the change in hours, not in ice creams.
- If you answered 215
- 215 adds the intercept to the difference.
- If you answered 335
- 335 is the prediction for 8 hours alone.
More Problem-Solving and Data Analysis questions
- Medium
A car travels 150 miles in 2.5 hours. At this rate, how far will it travel in 4 hours? - Medium
The price of a stock rises from $40 to $50. What is the percent increase? - Medium
Based on the model, what score does the line predict for a student who studies 5 hours? - Medium
A population decreases from 250 to 200 over a year. What is the percent decrease? - Medium
If one person is chosen at random from those who prefer tea, what is the probability the person is under 30? - Medium
What is the difference between the mean and the median of this data set?
Not affiliated with the College Board. SAT is a trademark of the College Board.