Asked by Kyle
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)
Answers
Answered by
PsyDAG
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.
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.