Question 1190149
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The mean age of students at a high school is 16.5 with a standard deviation of 0.7 
you use the standard normal table to determine that the probability of selecting 
one student at random whose age is more than 17.5 years is about 8% 
what is the error in this problem?
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I want to convince you that the statement in the post is non-sensical.


Let consider one academic year, let say from September to May, inclusive.


In the post, the mean age is considered as a real number continuous variable (since it uses decimals etc.)


But this "mean" (defined and used this way as a real decimal number) CHANGES during the academic year,

which is not reflected in the problem.



                Again: during the academic year, such a conception 
        as a mean students age does not exist as a fixed real continuous decimal variable. 



I do not know if I answered your question - - - it was not my goal.


My goal was to explain that the conception does not exist, which is discussed in the post.