The median estimated height of the building is 8m.
The median estimated height can be found by arranging the given data in increasing order and finding the middle value.
The stem-and-leaf diagram shows the following results for estimating the height of a building:
6 | 5 represents 6.5m
6 5
9 7 0 2 6 8 8 8 3 3 5 7 7 9 9 0 5 5 5 10 4 8 11 2 7
There are a total of 21 data points.
The middle value would be the 11th value when arranged in increasing order.
Therefore, the median estimated height is 8m.