document.write( "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). \n" ); document.write( "
Algebra.Com's Answer #782119 by Boreal(15235)\"\" \"About 
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.
\n" ); document.write( "You can then use normalcdf (-6,15/7) and subtract normalcdf (-6, -10/7)
\n" ); document.write( "or easier normalcdf (40,65,50,7) and you get 0.9074\r
\n" ); document.write( "\n" ); document.write( "Draw a normal curve, and put 0 at the middle. Go out 3 sd s on both sides.
\n" ); document.write( "label the middle 50, and +1 sd is 57, +2 sd 64 and +3 sd 71
\n" ); document.write( "on the left -1sd is 43, -2 sd is 36 and -3 sd is 29
\n" ); document.write( "Shade the area between 40 and 65 and you will have an idea that it is almost all the normal curve (9/10)
\n" ); document.write( "
\n" );