The method of tree ring dating gave the following years A.D. for an archaeologic
ID: 3294474 • Letter: T
Question
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. 1201 1243 1201 1278 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.
Explanation / Answer
from above mean x=42
and std deviaiton s =14
b) for (n-1=8) degree of freedom and 90% CI ; t=1.8595
therefore 90% confidence interval lower limit =sample mean - t*std error =1238
90% confidence interval upper limit =sample mean + t*std error =1290
X 1201 1243 1201 1278 1268 1316 1275 1317 1275 mean(X) 1263.7778 std deviation(S) 42.3461 std error =S/(n)1/2 14.1154