Answer:
16,
Step-by-step explanation:
1) Put numbers in ascending order
15, 16, 17, 17, 19, 19, 23, 24
2) Find the middle numbers use n+1/2
n = the amount of numbers in the sequence
8+1/2 = 4.5
3) The answer is 18 because that's the number between 17 and 19
