The mean resting heart rate of an adult male is 71 beats per minute (bpm) with a standard deviation of 11 bpm. The mean resting heart rate of an adult female is 80 beats per minute (bpm) with a standard deviation of 14 bpm. Malik is a male athlete with a resting heart rate of 50 bpm. Fern is a female athlete with a resting heart rate of 51 bpm.

a. Who has a lower heart rate relative to other adults of the same sex? Justify your answer using z-scores.

b. Would the resting heart rate of either of these two be considered significantly low? Explain based on your answer to part (a).