Answer: 66.5
Explanation:
Given data : 50 52 68 64 65 61 68 75 75 78
Step 1 : Arrange the data in an order .
50 52 61 64 65 68 68 75 75 78
Step 2 : Then , calculate the number of elements.
The number of data values in the given data = 10
Since , the data is even then the median of the data will be the mean of the two middlemost values.

Hence, the median of the data set = 66.5