SOLUTION: A survey of college students was conducted during final exam week to assess the number of hours spent studying each day. The mean number of hours was 5 with a standard deviation of

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Question 1167974: A survey of college students was conducted during final exam week to assess the number of hours spent studying each day. The mean number of hours was 5 with a standard deviation of 1.5 hours. The distribution was normal.
1.What percentage of students studied 7 or more hours per day?


2.What percentage of students studied 2 or more hours per day?


3.What percentage of students studied between 2 and 7 hours per day?
Answer by amarjeeth123(569) About Me  (Show Source):
You can put this solution on YOUR website!
This is a standard normal distribution or Gaussian curve.
mu=5 hours
sigma=1.5 hours
z=(x-mu)/sigma
z1=(7-5)/1.5=2/1.5=4/3=1.3333
This can be done in Excel.
P(x>7hours)=1-P(x<=7hours)=1-0.90878878=0.0913(approx)

The other two bits can be solved the same formula.
Hence proved.