Answer
The mean is 59.2167, no mode, the median is 57.835,, the midrange is 60.345.
Work Step by Step
The mean can be counted by summing all the data and dividing it by the number of data: $\frac{55.99+69.99+48.95+48.92+71.77+59.68}{6}=59.2167$, the mean is 59.2167. The mode is the data occuring the most times but here all data occurs one time, therefore there is no mode. The median is the average of the 1 or 2 (here 2) middle data: (59.68+55.99)/2=57.835, the median is 57.835. The midrange is the average of the highest and the lowest data: (71.77+48.92)/2=60.345, the midrange is 60.345. We don't really have a most important statistic nor do we require a new one.