To determine the percentage of people surveyed who can swim, we need to analyze the given relative frequency table. The table provides the proportion of adults and children who can swim and cannot swim.
Let's break down the table data:
1. Adults:
- The relative frequency of adults who can swim is 0.34.
- The relative frequency of adults who cannot swim is 0.06.
2. Children:
- The relative frequency of children who can swim is 0.48.
- The relative frequency of children who cannot swim is 0.12.
To find the total proportion of people who can swim, we need to add the proportions of adults and children who can swim:
[tex]\[
\text{Proportion of adults who can swim} = 0.34
\][/tex]
[tex]\[
\text{Proportion of children who can swim} = 0.48
\][/tex]
[tex]\[
\text{Total proportion of people who can swim} = 0.34 + 0.48 = 0.82
\][/tex]
To convert this total proportion into a percentage, we multiply by 100:
[tex]\[
\text{Total percentage of people who can swim} = 0.82 \times 100 = 82\%
\][/tex]
Thus, the percentage of the people surveyed who can swim is:
D. [tex]\( \boxed{82\%} \)[/tex]