Difference between revisions of "TMean2Estimate Command"
From GeoGebra Manual
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− | ; | + | ;TMean2Estimate[<List of Sample Data 1>,<List of Sample Data 2>,<Level>,<Boolean Pooled>] |
: Calculates a T confidence interval estimate of the difference between two population means using the given sample data sets and confidence ''Level''. | : Calculates a T confidence interval estimate of the difference between two population means using the given sample data sets and confidence ''Level''. | ||
: If ''Pooled'' = true, then population variances are assumed equal and sample standard deviations are combined in calculation. | : If ''Pooled'' = true, then population variances are assumed equal and sample standard deviations are combined in calculation. |
Revision as of 02:39, 23 July 2011
- TMean2Estimate[<List of Sample Data 1>,<List of Sample Data 2>,<Level>,<Boolean Pooled>]
- Calculates a T confidence interval estimate of the difference between two population means using the given sample data sets and confidence Level.
- If Pooled = true, then population variances are assumed equal and sample standard deviations are combined in calculation.
- If Pooled = false, then population variances are not assumed equal and sample standard deviations are not combined.
- Results are returned in list form as {lower confidence limit, upper confidence limit}.
- TMean2Estimate[<Sample Mean 1 >,<Sample Standard Deviation 1 >, <Sample Size 1>, <Sample Mean 2 >,<Sample Standard Deviation 2 >, <Sample Size 2>, <Level>,<Boolean Pooled>]
- Calculates a T confidence interval estimate of the difference between two population means using the given sample statistics and confidence Level. Results are returned in list form as {lower confidence limit, upper confidence limit}.
- Pooled is defined as above.
Note: This interval has definition: (sample mean1 - sample mean2) ± t* SE, where
- n1, n2 = sample sizes
- s1, s2 = sample standard deviations
- If pooled = true
- sp = pooled standard deviation
- SE = sp * sqrt(1/n1 + 1/n2)
- t* = critical value for given confidence Level and T distribution with degrees of freedom = n1 + n2 - 2.
- If pooled = false
- SE = sqrt(s1^2/n1 + s2^2/n2)
- t* = critical value for given confidence Level and T distribution with degrees of freedom given by the Welch-Satterthwaite approximation .
- If pooled = false