18. Radiation in Baby Teeth Listed below are amounts of strontium-90 (in milli- becquerels) in a simple random sample of baby teeth obtained from Pennsylvania residents born after 1979 (based on data from "An Unexpected Rise in Strontium-90 in U.S. Decidu- ous Teeth in the 1990s," by Mangano, et. al., Science of the Total Environment). Construct a frequency distribution with eight classes. Begin with a lower class limit of 1 10, and use a class width of 10. Cite a reason why such data are important. 155 142 149 130 151 163 151 142 156 133 138 161 128 144 172 137 151 166 147 163 145 116 136 158 114 165 169 145 150 150 150 158 151 145 152 140 170 129 188 156