The method of tree ring dating gave the following years A.D. for an archaeologic
ID: 3217692 • 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.
(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.)
(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.)
Explanation / Answer
Solution:
a)
Mean = 1287.1111
Standard deviation = 28.0733
b)
The t-critical value for a 90% confidence interval with n-1=9-1=8 degrees of freedom is 1.86
Sample mean = 1287.1111
Standard deviation = 1287.1111
Standard error of mean = / n
Standard error of mean = 28.0733 / 9
Standard error of mean 9.3578
Confidence interval 1287.1111-(9.3578)(1.86) and 1287.1111+(9.3578)(1.86)
(1269.7056, 1304.5166)
You may want ro round the lower and upper limits.