Apackage has a mean mass of 340 g and a standard deviation of 1.5 g. assuming that the masses are normally distributed, find the percent of packages with a mass below 336.7 g

The z-score for a weight of 336.7g is found as follows;

The cumulative probability for a z-score of -2.2 can be found from a normal distribution table:
The cumulative probability for a z-score of -2.2 is 0.0139.
Therefore the answer is 1.39%.