Which of the following is most likely the next step in the series?

which of the following sets of data would produce the largest value for an independent-measures t statistic? the two sample means are 10 and 20 with variances of 20 and 25 the two sample means are 10 and 20 with variances of 120 and 125 the two sample means are 10 and 12 with sample variances of 20 and 25 the two sample means are 10 and 12 with variances of 120 and 125

Evaluate cos2θ for cosθ = square root of 3/2

Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15