A contractor claims every fifth call has a bad connection. How many good calls in a row do you need to disprove him? This post uses a binomial hypothesis test to calculate the exact sample size for 99% confidence — with the Google Sheets formula included.

Stop guessing how many calls to audit. Use this statistical formula to calculate the exact sample size needed for call audits that prove quality improvements. Learn about confidence levels, power calculations, and A/B testing verification for your sales team.