# Finding patterns in seemingly arbitrary pairs of numbers

I don't work (directly) in mathematics (I'm a programmer), but I see numbers every day. Today I came across an issue where some totals were off, and was sent a list of the last 9 examples of the issue. Of course I love numbers and patterns, so I was intrigued:

I noticed almost immediately that all 9 of the "Correct"/"Incorrect" pairs had the same decimal value in the hundredths place, and decided to quickly calculate the difference of each in an effort to see some sort of pattern and help lead me to an a-ha moment. Well, we determined that the issue wasn't on our end, however the data was way too interesting for me to simply discard! :D

Two Questions (sorry they are unrelated):

1. Is there an obvious pattern I'm missing here? Obviously, context matters, however this is all of the relevant data I have.

2. How would one calculate the odds that this is an anomaly? I know "anomaly" has no direct representation in mathematics, so it's probably up for interpretation. Obviously, the odds that 9 pairs of random numbers with two decimal places would match the hundredths position is 1/1,000,000,000, but I don't think it's fair or realistic to say that there's only a one in a billion chance this number set is an anomaly.

• Another thing that strikes me is the multiples of $4.9: \, 9.8, 14.7, 19.6$ as well as $1.9 + 7.9 = 9.8$ – Henry Sep 1 '15 at 22:03
• Not to mention that $E_n=E_{n+2}$ for $n=3,6,7$ (Where $E_i$ is the error in the $i^{th}$ place). – lulu Sep 1 '15 at 22:07
• @Henry Yea I saw that immediately as well. Unfortunately the differences don't increase with the numbers, so I would guess there is another number associated with this pair that is influencing the difference. – Keith Sep 2 '15 at 14:06

seem to be powers of $2$ times $1.9. \; 4.9, \; 7.9, \; 10.9, \; 13.9, \ldots$
powers of 2 are expected on a computer, no idea what would cause $3k+ 1.9$ or $3w - 1.1$