Continuity Correction Calculator

When to Use This Calculator

The Continuity Correction Calculator is used when approximating a discrete probability distribution (like the binomial distribution) with a continuous one (like the normal distribution). This is common in statistical hypothesis testing when sample sizes are large.

How to Use the Calculator

1. Enter your sample size (n) - the number of trials or observations
2. Enter the probability (p) of success for each trial
3. Select your alternative hypothesis type (two-sided, less than, or greater than)
4. Click "Calculate" to determine the appropriate continuity correction factor

Understanding the Results

The calculator provides a z-value that represents the continuity correction factor. This value is used to adjust the boundaries when approximating a discrete distribution with a continuous one:

• For a two-sided test, use the z-value for α/2
• For a one-sided test, use the z-value for α

Practical Example

Suppose you're conducting a binomial test with n=100 and p=0.05, and you want to test if the number of successes is significantly less than expected. With a significance level of 0.05, the continuity correction factor would be approximately 1.645. This means you would adjust your normal approximation by 0.5 in the direction of the test when calculating probabilities.

Formula

The continuity correction factor is based on the z-score corresponding to your significance level (α) and test type:

For two-sided tests: z_c = z_α/2

For one-sided tests: z_c = z_α