Respuesta :
Answer:
81.85.
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
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.
Suppose the mean height for men is 70 inches with a standard deviation of 2 inches.
This means that [tex]\mu = 70, \sigma = 2[/tex]
What percentage of men are between 68 and 74 inches tall?
The proportion is the p-value of Z when X = 74 subtracted by the p-value of Z when X = 68.
X = 74
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{74 - 70}{2}[/tex]
[tex]Z = 2[/tex]
[tex]Z = 2[/tex] has a p-value of 0.9772.
X = 68
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{68 - 70}{2}[/tex]
[tex]Z = -1[/tex]
[tex]Z = -1[/tex] has a p-value of 0.1587.
0.9772 - 0.1587 = 0.8185
0.8185*100% = 81.85%.
Thus the percentage is 81.85%, and the answer is 81.85.
