Competitive prices?

A retailer entered into an exclusive agreement with a supplier who guaranteed to provide all products at competitive prices. The retailer eventually began to purchase supplies from other vendors who offered better prices. The original supplier ?led a legal action claiming violation of the agreement. In defense, the retailer had an audit performed on a random sample of invoices. For each audited  invoice, all purchases made from other suppliers were examined and the prices were compared with those offered by the original supplier. For each invoice, the percent of purchases for which the alternate supplier offered a lower price than the original supplier was recorded.35 Here are the data:

0  100     0  100     33      34  100     48      78  100     77   100  38

68   100   79   100   100   100   100   100  100    89   100  100

Report the average of the percents with a 95% margin of error. Do the sample invoices suggest that the original supplier's prices are not competitive on the average?