Mean: Mean Is You add all and you divide then by how many numbers you have Like 21+42+63+84+105+126+147=504
504÷7=72
Medium: Is the Middle Number of the Set
So whats the Middle number of the set?
21, 42, 63, 84, 105, 126, 147
84 Is in the Middle of the set
Mode: is when the Number is Repeated different times in the set
But in this set we don't have Multiple of the the same Number so heres an Example
13, 13, 13, 13, 14, 14, 16, 18, 21
So you see 13 Is the Most common Number for so 13 is the Mode.
Which for your answer (Median) The Answer is 84.
