Education Technology

Solution 28770: Correcting a Domain Error when Calculating a 1-Prop Z-Test on a Graphing Calculator.

When trying to calculate a 1-Prop Z-Test, I get a domain error on my graphing calculator.

When calculating a 1-Prop Z-Test with the number of successes provided as a percentage, the calculation will result in a domain error unless the success percentage is converted to a value.


Example: The hypothesized proportion is .9, with 80% successes, and a sample size of 200. For this example, p=.9, and n=200, but x cannot be entered as .8, as a partial success is not possible.

Instead, x would be 80% of the sample size of 200 or 200*.8=160, so x=160. The correct values would be entered as:


For more information please refer to the graphing calculators guidebooks.