To solve this problem, we will use the following expression:
[tex]\frac{favorable\text{ outcomes}}{total\text{ outcomes}}.[/tex]In this case:
[tex]\begin{gathered} Total\text{ outcomes}=21+6+6=33, \\ favorable\text{ outcomes}=6. \end{gathered}[/tex]Substituting the above values in the expression, we get:
[tex]\frac{6}{33}.[/tex]Finally, simplifying the above result, we get that the probability that his shirt number is from 67 to99 given that he weighs at most 210 pounds is:
[tex]\frac{2}{11}.[/tex]Answer:
[tex]\frac{2}{11}.[/tex]