Dipesh is the project manager and trying to estimate the cost of an activity. in the optimistic scenario he thinks the activity is expected to cost only $$6,000,$ in the pessimistic scenario this number is $$24,000$ and the most likely case number is $$18,000.$ What is the expected activity cost $($use three$-$point estimation $($beta$)?0$$$1)17,0000$$

$2)15,0000$$

$3)18,000$ $

$4)24,000$