Find the area under the standard normal curve over the inter
     Find the area under the standard normal curve over the interval z = -0.23 to z = 0.23. Compute probabilities using the standard normal table in  Round the answer to four decimal places. 
  
  Solution
Mean ( u ) =0
 Standard Deviation ( sd )=1
 Normal Distribution = Z= X- u / sd ~ N(0,1)                  
 To find P(a < = Z < = b) = F(b) - F(a)
 P(X < -0.23) = (-0.23-0)/1
 = -0.23/1 = -0.23
 = P ( Z <-0.23) From Standard Normal Table
 = 0.40905
 P(X < 0.23) = (0.23-0)/1
 = 0.23/1 = 0.23
 = P ( Z <0.23) From Standard Normal Table
 = 0.59095
 P(-0.23 < X < 0.23) = 0.59095-0.40905 = 0.1819

