The number of chocolate chips in an 18ounce bag of chocolate

The number of chocolate chips in an 18-ounce bag of chocolate chip cookies is normally distributed with a mean of 1300 chocolate chips and a standard deviation of 80 chocolate chips. What is the probability that a randomly selected 18-ounce bag of chocolate chip cookies contains fewer than 1100 chocolate chips?

Solution

Normal Distribution
Mean ( u ) =1250
Standard Deviation ( sd )=100
Normal Distribution = Z= X- u / sd ~ N(0,1)                  
P(X < 1400) = (1400-1250)/100
= 150/100= 1.5
= P ( Z <1.5) From Standard Normal Table
= 0.9332