In a certain distribution the mean is 50 with a standard deviation of 4 tell the probability that a number lies between 42 and 68?
Calculate the Z value and determine the area (probability)
between the Z values. Z = (x-mu)/sigma. Z42 = (42-50)/4 = -2 &
Z68 = (68-50)/4 = 4.5. Go to the related link and the areas are
.0228 & for 4.5 use .9999. Subtract the two values; .9999 -
.0228 = .9771.