Question

The data in the table compares x, the number of pages in a chapter, to y, the amount of time, in minutes, spent reading. The function y = 0.86x – 0.09 models the data in the table.

A 2-column table with 5 rows. The first column is labeled pages in a chapter with entries 10, 12, 5, 26, 20. The second column is labeled time spent reading (minutes) with entries 8, 11, 4, 22, 17.
Which is the best prediction for the number of pages in a chapter that takes 18 minutes to read?

15
17
19
21

Answer 1

Use the inverse of the model: x = (y + 0.09)/0.86.
For y = 18: x = (18 + 0.09)/0.86 = 18.09/0.86 ≈ 21.03, so the best prediction is 21 pages.