Chapter 3 Test

Which if the following statements is true?

A. Converting units of measure (such as changing mm to cm) does not affect the correlation coefficient

How would the removal of point A affect the slope of the LSRL

A. The slope of the LSRL would decrease

There is a positive correlation between the size of a hospital (measured by number of beds) and the median number of days that patients remain in the hospital. Does this mean that you can shorten a hospital stay by choosing to go to a small hospital?

B. No- the positive correlation is probably explained by the fact that seriously ill people go to large hospitals.

How would the removal of point A affect the correlation coefficient?

B. The correlation coefficient would become stronger

Which of the following statemnets is false?

B. The slope of a line is the amount by which x increases when y increases one unit

Which of the following statements is true?

C. The value of the coefficient of determination is always between zero and one, inclusively.

Which of the following statements is correct about the amount of air pollution in the cost of medical care per person over age 65 or six you graphical regions of the US?

C. There is a moderate, negative, linear association between the amount of air pollution in the cost of medical care for a person over age 65

A particular set of bivariate data produces the following results: x=8, sx=5.2, y=6.4, sy=1.8 find the slope of the LSRL if tge yintercept is 3.2

D. .4

Which of the following statements about the correlation coefficient is false?

D. A correlation of one indicates a perfect cause-and-effect relationship between the variables

The least squares regression line

E. Is the line which has all of the above properties

Which of ghe following pairs of variables would have a negative correlation coefficient?

E. as A hiker climbed a mountain: the altitude and the temperature