Jenna works in an ice cream shop. When she starts her shift the tub of chocolate ice cream is 2/3 full. When she finishes her shift 6 1/2 h later, there is only 1/6 of the tub left. What was the average hourly change in tub fullness?

Assume that the weights of quarters are normally distributed with a mean of 5.67 g and a standard deviation 0.070 g. a vending machine will only accept coins weighing between 5.48 g and 5.82 g. what percentage of legal quarters will be rejected? round your answer to two decimal places.