Federalworkplace safety standards for noise levels state that personal protective equipment is required if the time-weighted sound level at awork site exceeds 90 dBA. Suppose that this is interpreted as saying that themean sound level at a site should not significantly exceed 90 dBA. At one location on its fabrication floor, a manufacturer records sound levels over 10 randomly selected time intervals.
Should the company begin requiring ear protection, if:

(a) ¯x = 81.2, s = 10.4, α = 0.1?

(b) ¯x = 97.2, s = 10.4, α = 0.1?

(c) Why would α = 0.1 be more reasonable than α = 0.01 in this situation? LO.1