Question 446013
   <pre><font face = "Tohoma" size = 4 color = "indigo"><b> 
Hi,
*Note: {{{z =blue (x - mu)/blue(sigma/sqrt(n))}}}
 {{{(x -mu) }}} = 800 , n = 225 and {{{sigma = 4500}}}
    z = 800/4500/15 =  800/300 = 2.6667  P(z < 2.6667 = .9962
And z = -800/300 = -2.6667  P(z < -2.667) = .0038
 P( -2.667 > z < 2.6667) = .9962-.0038 = .9924