Question

pulse rates (in bpm) were collected from a random sample of males who are non - smokers but drink alcohol. the pulse rates before they exercised had a mean of 74.32 and a standard deviation of 20.8. the pulse rates after they ran in place for one minute had a mean of 123.78 and a standard deviation of 27.17. which of the following statements best compares the means? the pulse rates before they exercised had a lower average than the pulse rates after they ran in place for one minute. which of the following statements best compares the standard deviations? select an answer select an answer the pulse rates before they exercised had a higher average than the pulse rates after they ran in place for one minute. the pulse rates before they exercised had a lower average than the pulse rates after they ran in place for one minute. the middle of the pulse rates before they exercised was higher than the middle of the pulse rates after they ran in place for one minute. the middle of the pulse rates before they exercised was lower than the middle of the pulse rates after they ran in place for one minute. the pulse rates before they exercised were more consistent than the pulse rates after they ran in place for one minute. the pulse rates before they exercised were less consistent than the pulse rates after they ran in place for one minute.

Explanation:

First Question (Comparing Means)

We are given the mean pulse rate before exercise is 74.32 bpm and after exercise (running in place for one minute) is 123.78 bpm. To compare the means, we simply look at the numerical values. 74.32 is less than 123.78, so the pulse rates before exercise had a lower average than after.

The standard deviation before exercise is 20.8 and after exercise is 27.17. A lower standard deviation indicates more consistency (less spread) in the data. Since 20.8 < 27.17, the pulse rates before exercise were more consistent (less spread out) than after.

Answer:

The pulse rates before they exercised had a lower average than the pulse rates after they ran in place for one minute. (Corresponding to the option: "The pulse rates before they exercised had a lower average than the pulse rates after they ran in place for one minute")

Second Question (Comparing Standard Deviations)