32. 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:

105.6 90.9 91.2 96.9 96.5 91.3 100.1 105.0 99.6 107.7 103.3 92.4

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

b. Suppose that prior to the experiment, a value of
7.5 had been assumed. How many determinations would then have been appropriate to obtain

.10 for the alternative
95?