Answer:
Neither, they increase by the exact same amount.
Step-by-step explanation:
With the first data set you have a mean of 50 and a median value of 50 as well because to find a median of an even set of numbers you take the two middle values and average them together, in this case being 35 and 65 averaging out to 50. Adding 155 to this data set increases the mean to 65 and the median value to 65 as well, making this a trick question because the increase is the exact same.