How was the "Expected Results" table calculated in the picture below? I'm trying graph the probability of different results based on buying N number of scratch tickets. Imagine a game with 4 tiers or prizes.

Prize Value Number of tickets
100 4
10 40
1 100
0 846

What would my expected +/- results be 66% of the time if I bought 10 tickets? How does one figure that out?


picture-2.jpg