How do i find x in this question. i'm very confused.

Given a(-12,5) and b(12,29) find the point that divides the line segment ab three-eighths of the way from a to b

Apsychology student wishes to investigate differences in political opinions between business majors and political science majors at her college. she randomly selects 100 students from the 260 business majors and 100 students from the 180 political science majors. does this sampling plan result in a simple random sample? why or why not? no, because each group of 200 students in the sample does not have the same chance of being selected. yes, because each group of 200 students in the sample has the same chance of being selected. no, because each individual student does not have an equal chance of being selected. yes, because each individual student has the same chance of being selected.

Need showing work for this problem 56.25 ×25.80