Reference no: EM131914272

The digital music players produced by a large Canadian manufacturer during the first two months of 2010 were of poor quality. A random sample of 100 players was obtained during this time and the players were tested. It was determined that 25 of them were defective. As a result, quality control standards were then tightened. A random sample of 100 players was taken during the next two months, 11 of which were defective. Is there sufficient evidence to indicate that the new quality control standards were effective in reducing the proportion of defective digital music players? To answer this question, conduct a hypothesis test at the 5% level of significance.