Does chronic hepatitis c infection impact bone mineral density? in the general population of healthy young adults, bone mineral density is normally distributed, and density scores are standardized to have a mean of 0 and a standard deviation of 1 . a study examined the bone densities of a random sample of 28 adult men suffering from chronic hepatitis c infection. their mean standardized bone density was −0.61 . does this provide strong evidence that the mean standardized bone density of adult men suffering from chronic hepatitis c infection is less than 0 ? state: do adult men suffering from hepatitis c infection have a mean standardized bone density below 0 ? plan: let be the mean standardized bone density for adult men suffering from chronic hepatitis c infection. test an alternative hypothesis against the null hypothesis.