Question

The height (in feet) and volume of usable lumber (in cubic feet) of 32 cherry trees are measured by a researcher. The goal is to determine if volume of usable lumber can be estimated from the height of a tree. The results are plotted below.

(a) In this study, the response variable is

A. neither height nor volume. The measuring instrument used to measure height is the response variable.
B. volume.
C. height or volume. It doesn't matter which is considered the response.
D. height.

(b) The scatterplot suggests

A. there is a positive association between height and volume.
B. there is an outlier in the plot.
C. both A and B.
D. neither A nor B.


2. Now consider the following scatterplot of the weight of cars (in thousands of pounds) versus their gas mileage (mpg).  

(a) A plausible value for the correlation between weight and mpg is

A. -0.9
B. -1.0
C. +0.7
D. +0.2

Answer 1

1) a) Answer: B) volume. b) Answer: C) both A and B. 2) a) Answer: A) -0.9