:2. Diagram ? on page ? shows a histogram for the blood pressures of subjects in a certain survey, along with the normal curve which approximates it. The percentage who had blood pressures between 120mm and 140mm is exactly equal to a. 40% b. the area under the histogram between 120 and 140 c. the area under the normal curve between 120 and 140 d. 100% e. 0%