1. r = -0.426
2. r = -0.915
3. D. No. The student did not control the amount of free time, so the data only show correlation. Correlation does not imply causation, and in this case, there could be other factors affecting both free time and grades. Without controlling for those factors, it is not possible to conclude that more free time causes improved grades.
4. (1) Manipulation of the independent variable, (2) control of extraneous variables, (3) random assignment to conditions, and (4) measurement of the dependent variable.
1. What is the correlation coefficient for the following data set? Round to three decimal places.
x 3.0 7.3 4.5 3.3 7.6
y 9.8 8.3 8.6 9.8 8.8
r=
2.What is the correlation coefficient for the following data set? Round to three decimal places.
x 1.5 3.9 4.6 4.9 6.5 6.6 7.3 7.7
y −11 −1 −12 −5 −9 −28 −15 −29
r=
3 .A student is investigating if the amount of free time per week affects grades. He randomly surveys the students at his school and finds a linear relationship between the variables with a correlation coefficient of 0.62. Can the student conclude that more free time causes an improvement in
grades? Explain.(1 point)
A. Yes. The student controlled the grades, so the correlation implies causation.
B. No. The student did not control the grades, so the data only show correlation.
C.Yes. The student controlled the amount of free time, so the correlation implies causation.
D. No. The student did not control the amount of free time, so the data only show correlation.
4.What are the requirements for an experiment to be able to show that changes in one variable cause changes in another?(4 points)
1 answer
1 answer