Figure 5 shows the scatter plot for white spruce trees in the Jack Haggerty Forest at Lakehead University in Canada. A regression model produced by a spreadsheet (Fig. 5), after rounding, is h = 1.8d + 34 where d is Dbh in inches and h is the height in feet.

(A) Interpret the slope of this model.

(B) What is the effect of a 1-inch increase in Dbh?

(C) Estimate the height of a white spruce with a Dbh of 10 inches. Round your answer to the nearest foot.

(D) Estimate the Dbh of a white spruce that is 65 feet tall. Round your answer to the nearest inch.

Transcribed Image Text:

Height (ft) 80.0+ 70.0- 60.0- 50.0- 40.0- 30.0 20.0- 10.0+ 0.0+ 0.0 5.0 y = 1.80x + 33.98 10.0 15.0 Dbh (in.) Figure 5 Linear regression for white spruce trees :.. 20.0 25.0