From Brilliant.orghttps://brilliant.org/community-problem/inside-two-heads/?group=Hx4GtRTwegGe.
Consider the following experiment : You are given four coins. You toss them simultaneously and you get some sequence of heads and tails. Then you remove one of the coins and toss the remaining three coins. Finally remove one more coin and toss remaining two coins. Find the probability that in each of these three steps, you get at most two heads in each step.
Each dot in the dot plot represents the number of trials out of 100 trials in which there were at most two heads at each step.