Minimum​ "usual" value= ________ beats per minute ​(Type an integer or a​ decimal.)

Question

A certain group of test subjects had pulse rates with a mean of 80.1 beats per minute and a standard deviation of 10.5 beats per minute. Would it be unusual for one of the test subjects to have a pulse rate of 141.1 beats per​minute?

Minimum​ "usual" value= ________ beats per minute

​(Type an integer or a​ decimal.)

Answer 1

Compute z

z = (141.1 - 80.1)/10.5 = 5.8

141.1 would be 5.8 standard deviations above the mean - that would be very unusual.

Minimum usual value would be 2 standard deviations below the mean or 80.1 - 2*10.5 = 59.1