The table provides a person's cholesterol level at selected times during a 10-week treatment period.
| Time (weeks) | 0 | 2 | 6 | 10 |
|---|---|---|---|---|
| Level | 210 | 200 | 190 | 180 |
What is the average cholesterol level over the 10-week period, approximated by a trapezoidal sum with the subintervals [0, 2], [2, 6], and [6, 10]?