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statistics standard error?
So the problem is:
Given the following sample data, calculate the standard of error for the two sample t test statistics assuming the population cariances are not equal.
s1= 13 n1= 42 s2= 21 n2= 35
I just can;t find an equation in my notes that would help me find the answer to this.
2 Answers
- cvandy2Lv 61 decade agoFavorite Answer
When the population variances are not equal, then,
t = (x1bar-x2bar)/√((S1²/n1)+(S2²/n2))
And the degrees of freedom is
df = (S1²/n1 + S2²/n2)²/[(S1²/n1)²/(n1-1)+(S2²/n2)²/(n2-1)]
However, because your sample sizes are greater than 29, you can use
Z = (X1bar - X2bar)/√((S1²/n1)+(S2²/n2)) and not worry about degrees of freedom.
