Answer Happy

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 four decimal
places.)
x
= A.D.s= yr
(b)
When finding an 90% confidence interval, what is the critical
value for confidence level? (Give your answer to three decimal
places.)
tc =
What is the maximal margin of error when finding a 90%
confidence interval for the mean of all tree-ring dates from this
archaeological site? (Round your answer to the nearest whole
number.)
E =
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.