How many good trades to lift your average?

Question

You have made 6 trades averaging \40 of profit each. You want your overall average to reach \50, and you expect every future trade to make \70. Solve in your head. How many more trades do you need? Aim: under 20 seconds.

Accepted Answer

Work in deviations from the target average of \50. Right now your 6 trades each sit \10 below target, a deficit of 6 	imes 10 = \60 that future trades must erase. Each future trade at \70 is \20 above target, so it chips \20 off the deficit: \frac{60}{20} = 3 	ext{ trades}. Check: \dfrac{6(40) + 3(70)}{9} = \dfrac{240 + 210}{9} = \dfrac{450}{9} = 50. Exactly on target. Takeaway. Frame it as deficit versus surplus around the target: (existing shortfall) divided by (each new trade's excess over target) gives the count. Here 60 / 20 = 3. The same balancing logic answers "how many at-bats to re…

How many good trades to lift your average?

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