the first time sam stands on a weight scale, it reads 120 pounds. he tries again and it reads 100 pounds. he tries for the third time and it reads 140 pounds. not satisfied with these results, he uses another weight scale. the second weight scale reads 130 pounds on every try. his actual weight is 110 pounds. based on this information, which of the following statements is true? a. measurements of the first weight scale are not reliable b. measurements of the second weight scale are not reliable c. measurements of the second weight scale are not valid d. measurements of the first weight scale are not valid e. options a. and c. are correct f. options a, c, d are correct