Estimating Proportions With Confidence Calculator

Estimating proportions with confidence is crucial in various fields, from statistics to finance. Our calculator helps you do this accurately and efficiently.

1. Enter the two values you want to compare.
2. Select your desired confidence level.
3. Click ‘Calculate’.

The calculator uses the proportion confidence interval formula: x ± z * (p * (1 - p) / n)^0.5, where:

• x is the proportion,
• z is the z-score based on your confidence level,
• p is the proportion,
• n is the sample size (assumed to be large).

Confidence Intervals for Different Levels

Confidence Level	Z-Score
90%	1.645
95%	1.96
99%	2.576

• Always use a confidence level appropriate for your needs.
• Remember, higher confidence levels result in wider intervals.

What is a confidence interval?

A confidence interval is a range of values around an estimate that indicates the reliability of the estimate.

For more information, see the Statistics How To guide and the Khan Academy tutorial.