
Tests
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Description: This command compares the population means of two populations when population standard deviation is unknown. A 
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 | o1 — o2 | o1 | : sample mean of sample 1 data | |||
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 | o2 | : sample mean of sample 2 data | |
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 | 2 | x1σn−1: sample standard deviation of sample 1 | ||||
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 | n1 | n2 | x2σn−1: sample standard deviation of sample 2 | |||
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 | n1 | : size of sample 1 | 
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 | n2 | : size of sample 2 | 
This formula is applicable when the population standard deviations of the two populations are not equal. The denominator is different when the population standard deviations are equal.
The t distribution degrees of freedom df and xpσn−1 differ according to whether the population standard deviations of the two populations are equal.
When the two population standard deviations are equal (pooled)
df = n1 + n2 – 2
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When the two population standard deviations are not equal (not pooled)
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| Definition of Terms | 
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| μ1 condition : sample mean value test conditions (“≠” specifies  | ||||||||
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| List(1) : | 
 | list where sample 1 data is located | ||||||
| List(2) : | 
 | list where sample 2 data is located | ||||||
| Freq(1) : | 
 | frequency of sample 1 (1 or list name) | ||||||
| Freq(2) : | 
 | frequency of sample 2 (1 or list name) | ||||||
| Pooled : | 
 | On or Off | 
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| o1 : | 
 | sample mean of sample 1 data | ||||||
| x1σn−1 : | 
 | sample standard deviation of sample 1 (x1σn−1 > 0) | ||||||
| n1 : | 
 | size of sample 1 (positive integer) | ||||||
| o2 : | 
 | sample mean of sample 2 data | ||||||
| x2σn−1 : | 
 | sample standard deviation of sample 2 (x2σn−1 > 0) | ||||||
| n2 : | 
 | size of sample 2 (positive integer) | ||||||
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