In general, if the data is not normally distributed, we should use the median to summarize it. In our case, the data distribution is approximately constant, except for the outlier of $7600; therefore, the data is not normally distributed and we need to use the median to summarize.
Calculate the median of the data set as shown below
![3400,3600,3700,3800,3900,4000,41000,4300,7600\rightarrow\text{ ordered from least to greatest, 9 elements in total}]()

Thus, the answer is the median, which is equal to 3900.