hw3_soln3 - between TOST time and RBOT time. (b) The value...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Problem 3.11 (a) SS xy = 5530.92 - (1950)(47.92)/18 = 339.586667, SS xx = 251,970 - (1950) 2 /18 = 40,720,and SS yy = 130.6074 - (47.92) 2 /18 = 3.033711, so r = 033711 . 3 40720 586667 . 339 = .9662 There is a very strong positive correlation between the two variables. (b) Because the association between the variables is positive, the specimen with the larger shear force will tend to have a larger percent dry fiber weight. (c) Changing the units of measurement on either (or both) variables will have no effect on the calculated value of r , because any change in units will affect both the numerator and denominator of r by exactly the same multiplicative constant. Problem 3.12 (a) Using R: ## Read in the data file dat=read.csv(file.choose(),header=T) ## Assign variable names x=dat[,1] y=dat[,2] ## Calculate correlation coefficient cor(x,y)
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
A value of r = .9233 means that there is a strong positive linear relationship
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: between TOST time and RBOT time. (b) The value of r does not depend on which of the two variables is labeled as the x variable. Thus, had we let x = RBOT time and y = TOST time, the value of r would have remained the same. (c) The value of r does not depend on the unit of measure for either variable. Thus, had we expressed RBOT time in hours instead of minutes, the value of r would have remained the same. Problem 3.16 The value of the sample correlation coefficient using the squared y values would not necessarily be approximately 1. If the y-values are greater than 1, then the squared y-values would differ from each other by more than the y-values differ from one another. Hence, the relationship between x and y 2 would be less like a straight line, and the resulting value of the correlation coefficient would decrease....
View Full Document

Page1 / 2

hw3_soln3 - between TOST time and RBOT time. (b) The value...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online