The method of tree ring dating gave the following years A.D. for an archaeological excavation site. Assume that the population of x values has an approximately normal distribution.
1320 1201 1257 1180 1268 1316 1275 1317 1275
(a) Use a calculator with mean and standard deviation keys to find the sample mean year x and sample standard deviation s. (Round your answers to the nearest whole number.)
x =_____ A.D.
s =_____ yr
(b) Find a 90% confidence interval for the mean of all tree ring dates from this archaeological site. (Round your answers to the nearest whole number.)
lower limit _______ A.D.
upper limit ______ A.D.
1 answer
See later post, but use ±.05 for Z score.
1 answer