Which values can be used for a binominal variable?

• A. 0 and 1 only
• B. All of the above
• C. Only two values
• D. Non-numeric values allowed

Answer: (B)

Binary (binomial) variables represent two outcomes and are kept numeric so we can perform math and probability calculations. The standard coding is 0 for one outcome and 1 for the other, so the variable can take exactly two numeric values. That’s why it’s correct to say it can be 0 and 1, or simply that it has two values. Non-numeric values wouldn’t work in this context, because you need numbers to compute things like sums, averages, and probabilities. Therefore the statements describing two numeric values, typically 0 and 1, reflect the correct concept. An option claiming all of the above would be incorrect due to the non-numeric possibility.