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Formula Functions / Functions T to Z / ZTEST
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    This function returns the significance value of a z-test. The z-test generates a standard score for x with respect to the set of data and returns the two-tailed probability for the normal distribution.




    This function has these arguments:

    Argument Description
    array Array of data to test
    x Value at which to test
    sigma [Optional] Known standard deviation for the population; if omitted, the calculation uses the sample standard deviation


    If sigma is not specified, the calculated standard deviation of the data in array is used.

    The equation for calculating the z-test is as follows, where n is the number of data points.

    ZTEST Equation

    Data Types

    Accepts numeric data for all arguments. Returns numeric data.




    ZTEST({5,10,15,12,11,8,16,7},10) gives the result 0.355512703503418

    ZTEST({5,10,15,12,11,8,16,7},10,3) gives the result 0.318675944098237

    Version Available

    This function is available in product version 1.0 or later.

    See Also

    FTEST | TTEST | Statistical Functions