Z = (score-mean)/SEm
SEm = SD/√n
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability = .05 to get the Z score.
Insert data into first equation to get the score.
A random sample of 50 four-year-olds attending day care centers provided a yearly tuition average of 3987, with a population standard deviation of 630. Find the 90 percent confidence interval of the true mean. What is the upper bound of this interval? (Rounded to nearest whole number)
1 answer