Question

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.)

Answer 1

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:


`\bar{x}= (1229+1292+1187+1257+1268+1316+1275+ 1317+1275)/(9) \\ \\ = (11416)/(9) =1268`

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:


`90\% \ C. \ I.=1268\pm1.65\left((15)/(√(9))\right) \\ \\ =1268\pm\left((15)/(3)\right)=1268\pm5 \\ \\ =(1268-5, \ 1268+5)=(1263, \ 1273)`