In a study of ground motion caused by earthquakes, the peak velocity (in m/s) and peak acceleration (in m/s2) were recorded for five earthquakes.

The results are presented in the following table.

Velocity |
1.54 |
1.60 |
0.95 |
1.30 |
2.92 |

Acceleration |
7.64 |
8.04 |
8.04 |
6.37 |
5.00 |

a. Compute the correlation coefficient between peak velocity and peak acceleration.

b. Construct a scatterplot for these data.

c. Is the correlation coefficient an appropriate summary for these data? Explain why or why not.

d. Someone suggests converting the units from meters to centimeters and from seconds to minutes. What effect would this have on the correlation?

Chapter 8: bivariate correlational research - When you see two things that are related, and you think are related, but actually have nothing to do with one another To be causal - Covariance - Internal validity - Temporal precedence Correlational strength - As you get a measurement change by this much on this chart or whatever - You get the same ratio change on the other chart for the other variable - This means that they are changing at the same rate o Either moving at the same amount in the same direction [perfect correlation o Or moving at the same amount in the opposite direction [perfect correlation - When they don’t move at the same rate; imperfect correlation – this is what r