Of 2,000 persons who had received radiation treatment in childhood bec

Of 2,000 persons who had received radiation treatment in childhood because of an enlarged thymus, cancer of the thyroid developed in 30 and a benign thyroid tumor developed in 70. A comparison group consisted of 6,000 children who had received no such treatment (brothers and sisters of the children who had received radiation treatment). During the follow-up period, none of the comparison group developed thyroid cancer, but benign thyroid tumors developed in 15Calculate the relative risk for benign thyroid tumors. Using your own words, interpret the relative risk. Show your computation