Question

A certain group of test subjects had pulse rates with a mean of 73.1 beats per minute and a standard deviation of 10.7 beats per minute. Use the range rule of thumb to identify the limits separating values that are significantly low or significantly high. Is a pulse rate of 84.5 beats per minute significantly low or significantly​ high

Answer 1

A certain group of test subjects had pulse rates with a mean of 73.1 beats per minute and a standard deviation of 10.7 beats per minute. Use the range rule of thumb to identify the limits separating values that are significantly low or significantly high. Is a pulse rate of 84.5 beats per minute significantly low or significantly​ high

Solution: We are given:

$\mu=73.1, \sigma=10.7$

We have to find the limits that will separate the values that are significantly low or significantly high.

Rule of thumb is:

Lower limit $=\mu-2 \times \sigma$

Upper limit $=\mu+2 \times \sigma$

Therefore, the lower limit $= 73.1 - 2 \times 10.7=51.7$

the upper limit $= 73.1 + 2 \times 10.7=94.5$

Hence, the limits separating values that are significantly low or significantly high are $51.7,94.5$

Is a pulse rate of 84.5 beats per minute significantly low or significantly​ high

Answer: The pulse rate of 84.5 beats per minute is neither significantly low nor significantly high. The pulse rate of 84.5 beats per minute is usual.