# One Proportion Z Test Calculator

One Proportion Z Test is a hypothesis test to make comparison between a group to specified population proportion. Hypothesis test need an analyst to state a null hypothesis and an alternative hypothesis. The results are mutually exclusive. That is if one is true, the other one must be false and vice versa. Use this One Proportion Z Test statistics calculator to find the value of Z - test statistic by entering observed proportion, sample size and null hypothesis value.

## One Proportion Z Test Statistics Calculator

One Proportion Z Test is a hypothesis test to make comparison between a group to specified population proportion. Hypothesis test need an analyst to state a null hypothesis and an alternative hypothesis. The results are mutually exclusive. That is if one is true, the other one must be false and vice versa. Use this One Proportion Z Test statistics calculator to find the value of Z - test statistic by entering observed proportion, sample size and null hypothesis value.

Code to add this calci to your website

#### Formula

z = (p^ - p_{0}) / √p_{0}(1 - p_{0}) / n
**Where,**
p^ - Observed proportion,
p_{0} - Null hypothesis value,
n - sample size,
Z - test statistic

#### Example

Doctors recommend aspirin for their patients with headaches. To test this claim, a random sample of 92 doctors is obtained, indicating with observed proportion of 85%, null hypothesis value of 72%.

Observed proportion (p^{^}) = 85

= 85 / 100 = 0.85

Sample size ( n ) = 92

Null hypothesis value (P_{o}) = 72 / 100 = 0.72

Test Statistic (z) = (0.85 - 0.72) / √0.72 (1 - 0.72) / 92

= 0.13 / √0.72 (1 - 0.72) / 92

= 0.13 / 0.046811366

= 2.777103321