# Assignment 13: Correlation and Regression Worksheet:

**Assignment 13: Correlation and Regression Worksheet**

Name:

Neatly respond to each prompt. Show all work for full credit. Round to four decimal places.

1. For one month, 500 elementary students kept a daily record of the hours they spent watching television. The average number of hours per week spent watching television was 28. The researchers conducting the study also obtained report cards for each of the students. They found that the students who did well in school tended to spend less time watching television than those students who did poorly. Listed are several possible statements concerning the results of this research. Select each statement that you agree with based on this study.

a. The sample of 500 is too small to permit drawing conclusions about elementary students in general.

b. If a student decreased the amount of time spent watching television, his or her performance in school would improve.

c. Even though students who did well watched less television, this doesn’t necessarily mean that watching television hurts school performance.

d. I don’t agree with any of these statements.

2. Which of the following correlation values represents a perfect linear relationship between two quantitative variables? Select all that apply.

a. 0

b. .9

c. -1

d. 1

e. .5

3. If females of a certain species of lizard always mate with males that are .75 years younger than they are, what would the correlation between the ages of these male and female lizards be?

4. The correlation between two scores on tests was found to be exactly 1. Which of the following would not be true, regarding the corresponding scatterplot?

a. Every point would lie along a perfect straight line, with no deviations at all.

b. The slope of the best fitting line would be 1.

c. The best fitting line would have an uphill (positive slope).

d. All of the above are true.

5. Suppose the correlation between two variables, math achievement and math attitude was found to be .78. What does this tell us about the correlation between math attitude and math achievement?

a. Nothing; not enough information given.

b. The correlation is -.78.

c. The correlation is 1-.78 = .22.

d. The correlation is still .78.

6. We find that the correlation between educational level attained and yearly income is +0.72. This finding means that

a. income is one result of higher educational level.

b. lower income is associated with higher educational level.

c. people with lower educational levels tend to have lower incomes.

d. people with higher educational levels tend to have lower incomes.

7. Which of the following values is most likely to represent the correlation coefficient for the data shown in this scatterplot?

a. r = -0.67
b. r = -0.10 c. r = 0.71 d. r = 0.93 e. r = 0.96 f. r = 1.00 |

8. Suppose that a researcher found that undergraduate students who engage in a moderate amount of exercise are healthier that those who engage in either little exercise or in lots of exercise. This finding suggests what type of relationship between amount of exercise and degree of health? Select the correct answer.

a. a negative linear relationship

b. a positive linear relationship

c. a strong linear relationship

d. no linear relationship

9. Many studies have shown that high school students who study a foreign language tend to score higher on the Verbal portion of the Scholastic Aptitude Examination than high school students who do not study a foreign language. Can one reasonably conclude from this observation that studying the foreign language causes students to improve their verbal skills? Explain.

10. The number of people living on American farms has declined steadily during this century. For the farm population (millions of persons) from 1935 to 1980, the regression equation for estimating population from year is y = 1167 – .587 x.

a. Use the regression equation to estimate the number of people living on farms in 1950.

b. Use the regression line to estimate the number of people living on farms in 2013. Explain why it is not reasonable to use the regression equation to make this prediction (why did you get nonsense for your prediction?).

## Needs help with similar assignment?

We are available 24x7 to deliver the best services and assignment ready within 3-4 hours? Order a custom-written, plagiarism-free paper

Get Answer Over WhatsApp Order Paper Now