The degrees of freedom for a two-sample t-test is

Miriam is using a one-sample t-test on the following group:Subject #15: 6.5 hoursSubject #27: 5 hoursSubject #48: 6 hoursSubject #80: 7.5 hoursSubject #91: 5.5 hoursWhich of the following statements is true?a.)Miriam needs to use a t-test when the standard deviation is known.b.)The value for the degrees of freedom for Miriam's sample population is five.c.)The value for the degrees of freedom for Miriam's sample population is four.d.)The t-distribution that Miriam uses is taller and has thinner tails than a normal distribution.

In t-test, if the variances of two sampled populations of size 30 and 28 are assumed to be the same, what is the degrees of freedom of the test?1 point29275657

Assume there is a sample of n1=8,with the sample mean X1=39 and a sample standard deviation of S1=2,and there is an independent sample of n2=4 from another population with a sample mean of X2=35 and a sample standard deviation S2=5.In performing the pooled-variance t test,how many degrees of freedom are there?

In sample distribution, the degree of freedom is calculated as

For a one-tailed test (lower tail) with 22 degrees of freedom at 95% confidence, the value of t =Question 6Select one:a.1.383b.-1.721c.-1.383d.-1.717