78 Wind turbine blade stress. Refer to the Wind Engineering

(Jan. 2004) study of two types of timber—radiata pine and hoop pine—used in high-efficiency small wind turbine blades, presented in Exercise 21 . Data on stress ( y ) and the natural logarithm of the number of blade cycles ( x )

for each type of timber were analyzed by means of simple linear regression. The results are as follows, with additional information on the coefficient of determination:

Interpret the value of r 2 for each type of timber.

Transcribed Image Text:

Radiata Pine: = 97.37 -2.50x, r = .84 Hoop Pine: 122.03 -2.36x, r2 = .90