[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]

*Subject*: **[OASIS Issue Tracker] Created: (OFFICE-2311) ZTEST**

*From*:**OASIS Issues Tracker <workgroup_mailer@lists.oasis-open.org>***To*: office@lists.oasis-open.org*Date*: Wed, 13 Jan 2010 19:49:15 -0500 (EST)

ZTEST ----- Key: OFFICE-2311 URL: http://tools.oasis-open.org/issues/browse/OFFICE-2311 Project: OASIS Open Document Format for Office Applications (OpenDocument) TC Issue Type: Sub-task Components: OpenFormula Affects Versions: ODF 1.2 Reporter: Robert Weir 5.) ZTEST > TODO: OOo Calc and Gnumeric produce the same results. Excel (2007 > beta) claims to calculate the one-tailed test. > All produce different results than expected! What OOo Calc and > Gnumeric calculate is out of my scope. Excel tries to calculate the > probability by integrating from minus infinity to z and substracts > this from one. That would only be right, if the absolute value of z is > taken, not the signed z! (I speak already of the one-tailed results > for this case, so no confusion here.) > So, either I made a mistake/misinterpretation or all three apps don't > get it right(TM) Well, I'll test it in R. There is NO standard z-test, BUT the t-test will do it, too. [There is also the package 'TeachingDemos' wich does define the z-test] > > z.test(x, mu=15, sd=sd(x)) > > One Sample z-test > > data: x > z = 0.3111, n = 30.000, Std. Dev. = 8.803, Std. Dev. of the sample mean > = 1.607, p-value = 0.7557 > alternative hypothesis: true mean is not equal to 15 > 95 percent confidence interval: > 12.34980 18.65020 > sample estimates: > mean of x > 15.5 where x = 1..30 This same example gives a value of 0.38 in Calc. I have NO idea what 0.38 stands for. And I just noticed that it is impossible to compute a t-test on a single array in Calc against the expected mean - or did I miss something? [The t-test in R gives virtually identical results, because a sample size of 30 is large enough to approximate the z-distribution.] -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://tools.oasis-open.org/issues/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

**Follow-Ups**:**[OASIS Issue Tracker] Commented: (OFFICE-2311) ZTEST***From:*OASIS Issues Tracker <workgroup_mailer@lists.oasis-open.org>

**[OASIS Issue Tracker] Commented: (OFFICE-2311) ZTEST***From:*OASIS Issues Tracker <workgroup_mailer@lists.oasis-open.org>

[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]