We want to determine whether people exposed to the bacteria bacillus subtilis suffer from a reduction in their respiratory capacity. A measure of this capacity is the ratio "volume of air emitted for one second" divided by "total volume".For a person of normal constitution, this ratio is on average 0.80. It is thought that exposure to bacillus subtilis might decrease this average ratio.

a) Which of the following choices corresponds to the hypotheses you want to test?

OL Hop = 0.8 Hu = 0.8 O i Hap = 0.8 HU > 0.8 O ii. How = 0.8 H: W