Difference between revisions of "TMean2Estimate Command"
From GeoGebra Manual
m (1 revision: statistics commands) |
|||
| Line 2: | Line 2: | ||
<noinclude>{{Manual Page|version=4.0}}</noinclude> | <noinclude>{{Manual Page|version=4.0}}</noinclude> | ||
{{command|statistics}} | {{command|statistics}} | ||
| − | ;TTest2[<List of Sample Data 1>,<List of Sample Data 2>,< | + | ;TTest2[<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''. |
| − | ;TMean2Estimate[<Sample Mean 1 >,<Sample Standard Deviation 1 >, <Sample Size 1>, <Sample Mean 2 >,<Sample Standard Deviation 2 >, <Sample Size 2>, < | + | : 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| 1= This interval has definition: '''''(sample mean1 - sample mean2) ± t* SE''''', where | ||
| + | :: n1, n2 = sample sizes | ||
| + | :: s1, s2 = sample standard deviations | ||
| + | :: If pooled = true | ||
| + | ::: sp = [http://en.wikipedia.org/wiki/Pooled_variance 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 [http://en.wikipedia.org/wiki/Welch%27s_t_test Welch-Satterthwaite approximation] . | ||
| + | }} | ||
Revision as of 02:38, 23 July 2011
- TTest2[<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
