Professor Ted Woodruff has given the same multiple choice final exam in his Principles of Microeconomics class for last 10 years. After examining his records from the past 10 years, he finds that the scores have a mean of 76 and a standard deviation of 12. What is the probability Professor Woodruff’s current class with 36 sample students has a class average below 78?

In a recent telephone survey, 5,000 randomly selected teenagers were asked to cite their primary social network site. six of 10 teenagers said they use mybook as their primary social network site. a 95% confidence interval to estimate the true proportion of teenagers who use mybook as their primary social network site is found to be (0.2964, 0.9036). which of the following is a correct interpretation of the confidence level? ninety-five percent of all samples of this size would yield a confidence interval of (0.2964, 0.9036). there is a 95% chance that the true proportion of teenagers who use mybook as their primary social network site is in the interval (0.2964, 0.9036). ninety-five percent of the time, the procedure used to generate this interval will capture the true proportion of teenagers who use mybook as their primary social network site. ninety-five percent of all the samples of size 5,000 lie in the confidence interval (0.2964, 0.9036).