A survey on students revealed that 23 are younger than 19 ye

A survey on students revealed that 23% are younger than 19 years of age. What is the probability that the number of SUBWAY sandwich taker as their lunch in a random sample of 100 individuals will exceed 25? (Without Continuity Corrections)

Solution

Normal Distribution
Proportion ( P ) =0.23
Standard Deviation ( sd )= Sqrt (P*Q /n) = Sqrt(0.23*0.77/100)
Normal Distribution = Z= X- u / sd ~ N(0,1)                  
P(X > 0.25) = (0.25-0.23)/0.0421
= 0.02/0.0421 = 0.4751
= P ( Z >0.475) From Standard Normal Table
= 0.3174