Difference between revisions of "Documentation/How Tos/Calc: ZTEST function"
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* The validity of this measure is not clear; see for example the draft ODFF standard 16May08, and that Excel has referred to this as both a one-tailed and a two-tailed test. | * The validity of this measure is not clear; see for example the draft ODFF standard 16May08, and that Excel has referred to this as both a one-tailed and a two-tailed test. | ||
| − | * Calc and Excel produce different results. Excel calculates <tt>'''1 - NORMSDIST(z)'''</tt>. | + | * Calc and Excel produce different results for the 3 parameter version of this function. Excel calculates <tt>'''1 - NORMSDIST(z)'''</tt>. See [http://www.openoffice.org/issues/show_bug.cgi?id=90759 issue 90759]. |
Revision as of 20:51, 15 June 2008
ZTEST
Returns the result of a z-test.
Syntax:
ZTEST(data; μ σ)
- data is a range or array containg a random sample from a population (population assumed to have a normal distribution).
- μ is the (known) mean of the population.
- σ is the (known) standard deviation of the population. If omitted, it is estimated from the sample data by STDEV(data).
- ZTEST calculates the z statistic as
-
- and returns a probability based on that.
Example:
ZTEST(A2:A20; 9; 2)
- returns the result of a z-test on a sample A2:A20 drawn from a population with known mean 9 and known standard deviation 2.
See also:
Issues:
- The validity of this measure is not clear; see for example the draft ODFF standard 16May08, and that Excel has referred to this as both a one-tailed and a two-tailed test.
- Calc and Excel produce different results for the 3 parameter version of this function. Excel calculates 1 - NORMSDIST(z). See issue 90759.
