Radon is a colorless and odorless radioactive gas that can
accumulate in residential homes. High levels of exposure can lead
to health problems. Radon levels are measured in units of
picocuries per liter
(pCi/L).
The recommended radon level is less than 4
pCi/L.
A housing development has
109
residential homes. The homeowners association would like to
estimate the average radon level in the development. Because it
would be too expensive to measure every home, a random sample
of
29
homes was selected to be tested, and the average radon
level was found to be
1.2
pCi/L.
Assume from past studies the population standard deviation of
radon levels in homes is
0.5
pCi/L.
Complete parts a and b below.
a. Construct a 90% confidence interval to estimate the
average radon level in the housing development.
The 90% confidence interval to estimate the average radon
level is
pCi/L, pCi/L.