ZTestw_conf() returns the aggregated z confidence interval value for a series of values.
This function applies to z-tests where the input data series is given in weighted two-column format.
If the function is used in the load script, the values are iterated over a number of records as defined by a group by clause.
If the function is used in a chart expression, the values are iterated over the chart dimensions.
Syntax:
ZTest_conf(weight, value[, sigma[, sig]])
Return data type: numeric
Arguments:
- value: The sample values to be evaluated. A population mean of 0 is assumed. If you want the test to be performed around another mean, subtract that mean from the sample values.
- weight: Each sample value in value can be counted one or more times according to a corresponding weight value in weight.
- sigma: If known, the standard deviation can be stated in sigma. If sigma is omitted the actual sample standard deviation will be used.
- sig: The two-tailed level of significance can be specified in sig. If omitted, sig is set to 0.025, resulting in a 95% confidence interval.
Limitations:
Text values, NULL values and missing values in the expression value will result in the function returning NULL.
Example:
ZTestw_conf( Weight, Value-TestValue)
