At bingogala.com they offer a $500 prize for a coverall within 54 calls. You told me earlier that the probability of that at least 1 card in 600 will get a coverall in 54 calls is 3.21%. So in 380 days (to date) at 8 sessions per day they should have 97.58 $500 winners, right? However I counted only 76 winners on their home page. When I brought up my question about this in chat my husband and I were both banned from the site which really sent my antenna up? Sorry to be a pest but if they are running an unscrupulous site I want to know how to figure it out so that I can shout it far and wide with facts. Thank you for any help you can give me in this matter.
First let me explain that this is a rather old question that I put on the back burner, bingogala has now been in operation for two years according to their home page. The probability of a coverall within 54 calls for a single card is COMBIN(75-24,54-24)/COMBIN(75,54) = 0.000054. The probability at least one card in 600 will get a coverall in 54 call is 1-(1-.000054)600 = 0.032121. The expected number of winners over 380 days at 8 sessions per day is 97.65. The standard deviation is (380*8*0.032121*(1-0.032121))1/2 = 9.72. So this is (97.58-76)/9.72 = 2.23 standard deviations south of expectations. The probability of 76 or fewer winners in a fair game is 1.30%. So this could either be explained by bad luck on the part of the players, or fewer than 600 players on average. Perhaps they didn’t get as many in the early days. So the evidence doesn't warrant an accusation of foul play in my opinion.