A sample of 12 radon detectors of a certain type was selected, and each was exposed to 1...

A sample of 12 radon detectors of a certain type was selected, and each was exposed to 100 pCi/L of radon. The resulting readings were as follows:

a. Does this data suggest that the population mean reading under these conditions differs from 100? State and test the appropriate hypotheses using α = .05.

b. Suppose that prior to the experiment a value of σ = 7.5 had been assumed. How many determinations would then have been appropriate to obtain β = .10 for the alternative μ = 95?