Answer: 103
Step-by-step explanation: The median is the middle number in the data set when the data set is written from least to greatest.
Notice that our data set is already written from least to greatest.
Now, we simply look at the number in the middle.
100, 102, 103, 106, 109
Notice that 103 appears in the middle of the data set.
This means that the median is 103.