Answer:
15 cm
Explanation:
The median is the number in the middle of a data set.
First, arrange the data from least to greatest.
10 cm, 15 cm, 15 cm, 18 cm, 20 cm
Now, take one number off each end of the data set until the middle number is reached.
10 cm, 15 cm, 15 cm, 18 cm, 20 cm
15 cm, 15 cm, 18 cm
15 cm
Therefore the median of the set of measurements is 15 cm.