Final answer:
Erin has the best rate because she completed the most jumping jacks per minute, which is the definition of having the best rate. In ranking average speed, the calculation is based on distance divided by time for Terri, Aaron, and Jamal.
Step-by-step explanation:
In order to determine who has the best rate of doing jumping jacks, we should consider the number of jumping jacks done per unit of time, which typically would be per minute. This is because a rate is a measure of something in relation to the time taken.
Choices (a) and (b) merely focus on who did the most jumping jacks overall, not considering time. Choice (d) considers who spent the most time doing jumping jacks, which does not necessarily correlate with having the best rate of jumping jacks. A person could spend a great deal of time doing the activity slowly. Therefore, the correct answer is (c) Erin has the best rate because she did the most jumping jacks per minute, which is the most efficient way to determine the rate of performance.
For the question involving walking distances and times (Terri, Aaron, Jamal), we would calculate their average speed by dividing the distance walked by the time taken and then rank them from lowest to highest average speed to determine the correct order.