Answer:
The z-score for a pulse rate of 147.6 beats per minute is 6.46 > 2, which means that this pulse rate is significantly high.
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the z-score of a measure X is given by:
![Z = \frac{X - \mu}{\sigma}](https://tex.z-dn.net/?f=Z%20%3D%20%5Cfrac%7BX%20-%20%5Cmu%7D%7B%5Csigma%7D)
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
By the Range Rule of Thumb, if Z < -2, the measure X is significantly low, and if Z > 2, the measure X is significantly high.
Mean of 75.2 beats per minute and a standard deviation of 11.2 beats per minute.
This means that ![\mu = 75.2, \sigma = 11.2](https://tex.z-dn.net/?f=%5Cmu%20%3D%2075.2%2C%20%5Csigma%20%3D%2011.2)
Is a pulse rate of 147.6 beats per minute significantly low or significantly high?
We have to find Z when X = 147.6. So
![Z = \frac{X - \mu}{\sigma}](https://tex.z-dn.net/?f=Z%20%3D%20%5Cfrac%7BX%20-%20%5Cmu%7D%7B%5Csigma%7D)
![Z = \frac{147.6 - 75.2}{11.2}](https://tex.z-dn.net/?f=Z%20%3D%20%5Cfrac%7B147.6%20-%2075.2%7D%7B11.2%7D)
![Z = 6.46](https://tex.z-dn.net/?f=Z%20%3D%206.46)
The z-score for a pulse rate of 147.6 beats per minute is 6.46 > 2, which means that this pulse rate is significantly high.