The correlation coefficient is used to determine a specific value of the x-variable given a specific value of the y-variable.

Select one:

True

False

If there is a very strong correlation between two variables, then the correlation coefficient must be much larger than 0 regardless of whether the correlation is negative or positive.

Select one:

True

False

A correlation coefficient is the square of the coefficient of determination.

Select one:

True

False

A correlation coefficient between temperature and air conditioning costs is -0.90 indicating increases in temperature cause air conditioning costs to go down.

Select one:

True

False

The covariance is

Select one:

a. A measure of the strength of the relationship between two variables.

b. Dependent on the units of measurement of the variables.

c. An unstandardized version of the correlation coefficient.

d. All of the above.

A study was done to compare the lung capacity of coal miners to the lung capacity of farm workers. The researcher studied 200 workers of each type. Other factors that might affect lung capacity are smoking habits and exercise habits. The smoking habits of the two worker types are similar, but the coal miners generally exercise less than the farm workers.

Which of the following is the explanatory (x) variable in this study?

Select one:

a. Occupation

b. Lung capacity

c. Exercise

d. Smoking or not