John, who is training with Margaret, has no heart monitor, and he cannot afford to buy one. He has to rely on his watch and his ability to measure his own pulse on his wrist. John is 27 years old and wants to train at the higher end of aerobic range, between 75% and 85% of his maximal heart rate. On his last run, John counted 30 heart beats in 15 seconds. Is he training within his target range?

It is difficult to say whether John is training within his target range due to his inability to measure his heart rate with a heart monitor. Also, taking his reading by himself could have some errors in it due to his inability to validate those readings.

In summary, though it is a tough action on his own part, it could still be safe to conclude that, he is within his target range going by the data he had.

Explanation:

1. d.

2.false

3.noise

too short

d would be your answer