Posted by Anonymous on .
A loaf of bread is normally distributed with a mean of 22 ounces and a standard deviation of .5 ounces.
What is the probability that a loaf of bread is < 20.75
The first thing you have to do is find the z score. z=(20.75-22)/.5 The z would be -2.5 Then, to find the probability, you can use your graphing calculator. Hit 2nd, then catalog, then go down to normalpdf. When that comes up, plug in -2.5 and it should give you a probability of .0175.
Hope that helps!
If you don't have a graphing calculator, you can find table in the back of your statistics text labeled something like "areas under normal distribution" to find the probability.
I hope that helps a little more.