In: Statistics and Probability
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.
| 1278 | 1180 | 1299 | 1208 | 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. |