5. Which is a correct interpretation of the UB and LB values? a. The mean difference in visual acuity score of the population of toddlers born prematurely and those carried to full term could plausibly be as low as the LB or as high as the UB. We are 95% confident that the sample mean difference in visual acuity scores of the population of toddlers born prematurely and those carried to full term is between the UB and LB values. b. Ninety-five percent of all scores are between the UB and LB values