To write a percentage as an odds ratio, convert the percentage to a decimal x , then calculate as follows: (1/ x ) - 1 = first number in the odds ratio, while the second number in the odds ratio is 1. Substitute your result from Step 3 for X  in the odds ratio X -to-1.

The chance of correctly choosing the Powerball is simply 1 in 26. figures together: 1 11,238,513 " 1 26 = 1 292,201,338 or 1 chance in 292,201,338. Step 1: The chance of getting 5 numbers correct out of 5 numbers drawn from 69 unique numbers is 1 in 11,238,513 (see #1, Step 1 above.)