Statistics
posted by Lily .
A soft drink vending machine is supposed to fill cups with pop. The cups hold exactly 8 oz of liquid. Suppose the actual amount dispensed by the machine follows a normal distribution with mean 7 oz. If it is found that exactly 4 percent of the cups overflow, what is the standard deviation of the normal distribution??
omg, please help.

A vending machine is designed to dispense a mean of 7.6 oz. of coffee into an 8oz cup. If the standard deviation of the amount of coffee dispensed is 0.4 oz. and the amount is normally distributed, find the percent of times that the machine will:
a.) Dispense from 7.4 oz. to 7.7 oz.
b.) Dispense less than 7.0 oz.