To which set or sets below does the number -7/8 belongs to ?

What number produces an irrational number when multiplied by -1.25

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

Can someone check if i did this correct. it’s number 4 if you’re wondering.