The document explains the degrees of freedom required for a statistical test involving unknown variances, assuming equal variances. It provides the formula for pooled variance and the test statistic, specifically for t-tests, highlighting the calculations involved. The critical value is determined using Student's t-distribution with the specified degrees of freedom.

1. State the degrees of freedom used in this test?
Write the formula for the pooled variance and interpret it.
What is the formula for the test statistic? Unknown Variances, Assumed Equal
tcalc=n1sp2+n2sp2where(x1x2)sp2=n1+n22(n11)s12+(n21)s22 For critical value, use Student's
twith d.f. =n1+n22