Greater Numbsville is comprised of three villages: Lower Numbsville
(LN, residents), Old Numbsville (ON, residents),
and Upper Numbsville (UN, residents). A crazed statistician
decides to do the following survey to estimate the average age of Greater
Numbsville residents. First he will flip a fair coin. If the coin comes up
heads he will obtain a simple random sample of six Greater Numbsville
residents. If the coin comes up tails he will instead do a stratified sample
of Greater Numbsville residents, using the three villages as strata, with
sample sizes of two for each stratum. He carries out his scheme and reports
the following data on the sampled residents.
To make your life difficult, however, the crazed statistician does not
report the outcome of the coin toss. Outsmart the crazed statistician by
using an unbiased procedure to report an estimate of the average age of
Greater Numbsville residents nonetheless. (HINT: use sampling weights.)
Report your answer to the nearest year.