In Exercise 43, we summarized the relationship between x = height of a student (in inches) and y = number of steps required to walk the length of a school hallway, with the regression line ŷ = 113.6 − 0.921x . For this model, technology gives s = 3.50 and r² = 0.399.

a. Interpret the value of s.

b. Interpret the value of r².

Exercise 43

The scatterplot shows the relationship between x = height of a student (in inches) and y = number of steps required to walk the length of a school hallway, along with the regression line ŷ =113.6−0.921x.

65 60 55 50 45 40 60 62 64 66 68 70 72 74 Height (in.) Number of steps