Question

If the partial pressure of carbon dioxide gas in a blood capillary is 45 mm hg, what is the pressure expressed in inches of mercury? 0.059 in. hg 1.8 in. hg 4.5 in. hg 1,100 in. hg 0.87 in. hg

Answer 1

Both inches of mercury and milimeters of mercury are units used to measure pressure . 
in. Hg - inches of mercury 
mm Hg - millimetres of mercury 
1 mm Hg is equivalent to 0.0394 in. Hg
therefore 45 mm Hg is equal to 0.0394 in.Hg/mm Hg x 45 mm Hg = 1.8 in. Hg

correct answer is B - 1.8 in. hg