Question 1159065: Assume that the random variable x is normally distributed, with mean “mu” = 50 and standard deviation “sigma” = 7. Draw, share ( I mean shade), & compute the normal curve with the area corresponding to the probability of P(40 < x <65).
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! You can use z=(x-mean)/sd which is -10/7 z for 40 and 15/7 for 65.
You can then use normalcdf (-6,15/7) and subtract normalcdf (-6, -10/7)
or easier normalcdf (40,65,50,7) and you get 0.9074
Draw a normal curve, and put 0 at the middle. Go out 3 sd s on both sides.
label the middle 50, and +1 sd is 57, +2 sd 64 and +3 sd 71
on the left -1sd is 43, -2 sd is 36 and -3 sd is 29
Shade the area between 40 and 65 and you will have an idea that it is almost all the normal curve (9/10)
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