Each distribution has a mean and standard deviation different from the others, but if they are all normal they will conform to the rule that 68 percent of cases will fall within 1 standard deviation of the mean:68 people in group 1 will have a height between 163 cm and 173 cm; 68 people in group 2 will have height ranging from 170 cm to 178 cm; and for group 3 the range is 178 cm to 182 cm