There's a laundromat that I go where I get countless anomalous-seeming coin observations. When I go into the laundromat, I always walk around looking for coins on the floor, and I virtually never find any. But then later on in the hour, one or two coins will tend to show up. I must have seen 70+ such coins that showed up at this laundromat after I had previously checked that there were no coins on its floor, and none of them were very close to people putting their clothes in the washers or dryers.
Yesterday it was the same old story. I went into the laundromat, and after putting my clothes in a washer, I looked around the floors to see if there were coins on the floor. There were none. Then about 30 minutes later I noticed a dime in a very noticeable spot where I had just walked past a few minutes ago without noticing such a dime. I had walked past the spot three times before that day without noticing any such dime, but now there was a dime in the spot. A few minutes later I found another dime on the floor.
In such cases I get a very strong feeling that the very improbable has happened. But is there way for me to mathematically verify the very high improbability of my coin sightings? There is one way.
Since 2014 the breakdown of the number of anomalous-seeming coins I have sighted is as follows: 121 pennies, only two nickels, 20 quarters, and 62 dimes, for a total of 205 coins. We can compare such numbers to the 2016 US production of pennies, nickels, dimes, and quarters. The US production numbers are as follows:
In light of such numbers, it seems very unusual that I have only got 2 nickels in my set of 205 anomalous-seeming coins. Given the fact that about almost 10 percent of the cents, nickels, dimes and quarters issued in 2016 were nickels, it seems that I should have got about 18 nickels, if mere chance was involved.
There is a way to calculate how improbable such a thing is. You can use what is called a binomial probability calculator. I tried using this binomial probability calculator at StatTrek.com to compute the odds of this. Below shows the inputs I used, and the output I got. The "number of trials" is the number of anomalous coin sightings I have logged, the number of successes is the number of nickels, and the probability is the probability (from the previous table) of getting a nickel (based on the 2016 mint production numbers).
What the calculator tells us is that given a probability of 0.0968113282 of finding a nickel when a coin might be either a penny, a nickel, a dime or a quarter, the chance of me getting only two or fewer nickels out of 205 random coins is less than 1 in a million. This is a very big hint that the anomalous coins I have noted are not just a random set of coins that accidentally fell to the ground. (I hadn't noticed how few of these coins were nickels until I had logged almost 200 observations of anomalous-seeming coin appearances.)
In this regard (the fact that I get so many mysterious dimes and pennies and so few nickels) my experience is consistent with the experience of others who report finding mysterious coins. Such people seem to report finding either dimes, pennies or both, with few reports of nickels appearing. When I do a Google search for “finding mysterious coins,” I find one page mentioning finding dimes and pennies, and two pages mentioning finding dimes. Then there is the “Finding Dimes” blog (www.findingdimes.org), in which a blogger reports 90+ anomalous dimes. The blog has many comments, largely from people finding anomalous dimes.
When I do a Google search for “finding mysterious dimes” or “finding mysterious pennies,” I get quite a few pages talking about finding mysterious dimes or mysterious pennies, but no sites with titles such as “Finding mysterious nickels.” When I do a Google search for “finding mysterious nickels,” I get some pages pages talking about finding mysterious dimes or mysterious pennies, but no sites with titles such as “Finding mysterious nickels.”
For me the most astonishing thing about this phenomenon is what I have seen countless dozens of times: I will notice a coin in a spot that I just walked past or very recently “coin-checked” without noticing any coin in that spot. You would have such an experience if you walked down a hall to your apartment door, put your key in your key slot, and then noticed a coin a meter to the left of your door that you failed to notice when walking right by such a spot a moment ago.