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.)

Given a table below which gives the years in A.D. for an archaeological excavation site using the method of tree ring dating:



Part A:

The sample mean is given by:



Therefore, the sample mean is 1268.

Part B:

We calculate the sample standard deviation as follows:



Part C:

The 90% confidence interval is given by: