Question

11-14. An article in Wood Science and Technology [“Creep

In Chipboard, Part 3: Initial Assessment of the Influence of

Moisture Content and Level of Stressing on Rate of Creep

and Time to Failure” (1981, Vol. 15, pp. 125–144)] studied

The deflection (mm) of particleboard from stress levels of relative

Humidity. Assume that the two variables are related according

To the simple linear regression model. The data are

Shown below: For question 11-14 in your textbook, what is the upper bound of a 95% confidence interval on the intercept?

X _ Stress level (%): 54 54 61 61 68

Y _ Deflection (mm): 16.473 18.693 14.305 15.121 13.505

X _ Stress level (%): 68 75 75 75

Y _ Deflection (mm): 11.640 11.168 12.534 11.224

Answer 1

The computations are done using R code. The code and output are shown below.

So the upper bound of a 95% Confidence interval for intercept term is 38.8710194.