Normal Probability Theorem :
The Z-score of the standard normal distribution is used under the normal probability to calculate the number of younger males. The Z-score is a measure of the standard deviation of the distribution from the mean value of the distribution.
Given: A group of 625 students has a mean age of 15.8 years with a standard deviation of 0.6 years. The ages are normally distributed.
How to find how many students are younger than 16.2 years?
Mean = 15.8
SD = 0.6
Z score = ( Value - Mean ) .SD
Value = 16.2 years
=> Z score = ( 16.2 - 15.8)/0.6 = 2/3 = 0.6667
from z score table :
0.7464 portion of students are younger than 16.2 years
=> 625 * 0.7464 = 466.5
= 466
Therefore, 466 Students are younger than 16.2 years.
Learn more about mean and SD on: https://brainly.com/question/1136789
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