Question

Estimating the Standard Deviation: Veterinary Science The resting heart rate
for an adult horse should average about 45 beats per minute with a (95% of
data) range from 22 to 70 beats per minute, based on information from The
Merck Veterinary Manual (a classic reference used in most veterinary colleges).
Let x be a random variable that represents the resting heart rate for an adult
horse. Assume that x has a distribution that is approximately normal.


(a) Estimate the standard deviation of the x distribution.

(b) What is the probability that the heart rate is less than 25 beats per minute?
(c) What is the probability that the heart rate is greater than 60 beats per
minute?
(d) What is the probability that the heart rate is between 25 and 60 beats per
minute?
(e) Inverse Normal Distribution: A horse whose resting heart rate is in the
upper 10% of the probability distribution of heart rates may have a secondary infection or illness that needs to be treated. What is the heart rate corresponding to the upper 10% cutoff point of the probability distribution?