Question 18442
  I wonder why you got stuck.

 when p = 0.94 . z = 1.555 (correct)
b) "This is where i have a problem, Given the formula x = SD*Z + mean
 i.e. (x - mean)/ sd =  z (regular form)
 Now, x =  87, z = 1.555, mean =  82.

 You can get the value of SD with baby algebra.

 Kenny