Representative data on x = carbonation depth (in millimeters) and y = strength (in mega pascals) for
Question:
Representative data on x = carbonation depth (in millimeters) and y = strength (in mega pascals) for a sample of concrete core specimens taken from a particular building were read from a plot in the article “The Carbonation of Concrete Structures in the Tropical Environment of Singapore” (Magazine of Concrete Research [1996]: 293-300);
Depth, x 8 20 20 30 35 40 50 55 65
Strength, y 22.8 17.1 21.1 16.1 13.4 12.4 11.4 9.7 6.8
a) Construct a scatterplot. Does the relationship between carbonation depth and strength appear to be linear?
b) Find the equation of the least-square line. • What would you predict for strength when carbonation depth is 25 mm?
c) Explain why it would not be reasonable to use the least-square line to predict strength when carbonation depth is 100 mm.
Business Statistics
ISBN: 978-0321925831
3rd edition
Authors: Norean Sharpe, Richard Veaux, Paul Velleman