A survey among freshman at a certain university revealed that the time spent studying the week before final exams was normally distributed with a mean of 25 hours and a standard deviation of 7 hours. What proportion of freshman students study less than 30 hours the week before final exams?

Which question is not a good survey question? a.don't you agree that the financial crisis is essentially over? 63on average, how many hours do you sleep per day? c. what is your opinion of educational funding this year? d.are you happy with the availability of electronic products in your state?