For a particular diamond mine, 80% of the diamonds fail to qualify as "gemstone grade". A random sample of 94 diamonds is analyzed. Find the probability that the proportion of the sample diamonds that fail to qualify as gemstone grade is between 0.76 and 0.83. A) 0.7673 B) 0.8340 C) 0.6013 D) 0.1660

The mean annual income for people in a certain city (in thousands of dollars) is 42, with a standard deviation of 30. A pollster draws a sample of 47 people to interview. Find the 84th percentile of the sample mean. A) 44.0 thousand dollars B) 46.3 thousand dollars C) 43.6 thousand dollars D) 49.0 thousand dollars