Question 1178715
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Solve each problem.
1. Your monthly electric bill has a mean of ₱120.00. what is the percentage that you will pay an amount between ₱1,380 and ₱1,740?

2.Suppose the scores in the mathematics exam are normally distributed. 
If the exam has a mean score of 25 and a standard deviation of 5, 
what is the probability that if you take the exam you will get a score higher than 30 points?
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(1) Problem in (1) is posed incorrectly/inaccurately: the standard deviation value is missed.



(2) Problem (2) in post by @CPhill is solved {{{highlight(highlight(incorrectly))}}}.



<pre>
If the score is higher than 30, it means that it is 31 or more.


So, we should calculate P(X >= 31).


It is  0.1151.   <U>the  CORRECT  ANSWER</U>


For fast calculations, I used free of charge solver at this site

https://onlinestatbook.com/2/calculators/normal_dist.html
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