Full-time college students report spending a mean of 23 hours per week on academic​ activities, both inside and outside the classroom. Assume the standard deviation of time spent on academic activities is 3 hours.   If you select a random sample of 100 ​full-time college​ students, there is an 89​% chance that the sample mean is less than how many hours per​ week?

Students in the psychology department at General State University consumes an average of 7 sodas per day with a standard deviation of 2.5.  the distribution is normal.  Explain how you would go about answering the following questions (include your answer to the question in your response): How many sodas would an individual at the 75thpercentile drink per day?

If you buy one ticket everyday for 365 days, find the mean and standard deviation for the numbers of winning tickets in such groups of 365 tickets. Round to three decimal places

Find the indicated IQ score. The graph to the right depicts IQ scores of adults, and those scores are normally distributed with a mean of 100 and a standard deviation of 15.