In: Statistics and Probability
Full-time college students report spending a mean of 30 30 hours per week on academic activities, both inside and outside the classroom. Assume the standard deviation of time spent on academic activities is 4 4 hours. Complete parts (a) through (d) below. b. If you select a random sample of 25 25 full-time college students, there is an 83 83% chance that the sample mean is less than how many hours per week?
µ = 30
σ = 4
n= 25
proportion= 0.8300
Z value at 0.83 =
0.954 (excel formula =NORMSINV(
0.83 ) )
z=(x-µ)/(σ/√n)
so, X=z * σ/√n +µ= 0.954 *
4 / √ 25 +
30 = 30.76
If you select a random sample of 25 25 full-time collegestudents, there is an 83 83% chance that the sample mean is less than 30.76 hours per week