Normal Distribution:

Inventory volume levels of a warehouse are found to be normally distributed over time, with an average of 670,000 cases and a standard deviation of 130,000 cases. The warehouse's capacity is 750,000.

a.) What is the probability that the capacity will be insufficient (i.e. inventory volume > capacity)?

b.) If the capacity would be expanded by 20% of the current, what would now be the probability of insufficiency?