68% are approximately within mean ± 1 SD
Z = ±1 = (score - mean)/SEm
SEm = SD/√(n-1) = approx. SD/10
Insert values in above Z equation to get scores.
a random sample of 100 college students is taken from the student body of a large university. assume that a population mean of 20 hours and a population standard deviation of 15 hours describes the weekly study estimates for the entire student body. About 68 percent of the sample means in this sampling distribution should be between?
2 answers
consider a normal distribution with mean 27 and standard deviation 6. What is the probability a value selected at random from this distribution is great than 27?