In: Statistics and Probability
The National Sleep Foundation (NSF) recommends that college students get between 8 and 9 hours of sleep per night. Not believing this is happening at a local college, a random sample of 20 students resulted in a mean of 6.94 hours, with a standard deviation of 1.1 hours.
Part 1 of 3
If it is assumed that hours of sleep for college students is approximately normally distributed, construct and interpret a 95% confidence interval statement as well as a confidence level statement. Do the students at this local college meet the NSF recommendation? (Round your answers to two decimal places. Use a table or technology.
Given, mean = 6.94 hours, standard deviation = 1.1 hours
Standard error of mean = = = 0.2459675
Degree of freedom, df = n-1 = 20 - 1 = 19
Critical value of t at 95% confidence interval and df = 19 is 2.093
95% confidence interval of hours of sleep for college students is,
(6.94 - 2.093 * 0.2459675, 6.94 + 2.093 * 0.2459675)
(6.43, 7.45)
Interpretation of 95% confidence interval statement - We're 95% confident that the interval (6.43, 7.45) captured the true mean hours of sleep per night for college students.
Interpretation of 95% confidence level statement - If we repeats this process many times, then about 95% of the intervals produced will capture the true mean hours of sleep per night for college students.
NSF recommends that college students get between 8 and 9 hours of sleep per night. Since the NSF recommendation range (8, 9) is outside the 95% confidence interval (6.43, 7.45), the local college does not meet the NSF recommendation