Stat indepenent

想請問咩係independent,點解個solution 話吾係independent，但係忽然又轉左d數之後就係independent？ 請好心人解答，吾該

Question:
A class of 100 engineering students can be separated into two
groups in two different ways, as follows.
Men Women Total
Mechanical 27 34 61
Electrical 16 23 39
Total 43 57 100
A student is chosen at random from the class.
Are the events \the student selected is a woman" and "the
student selected is an Electrical" independent?

Solution: P(Woman) = 0:57, whileP(WomanjElectrical) = 0:59. The events are
very nearly independent (but not quite).
Repeat the last question if the numbers in the class are as
follows.
Men Women
Mechanical 24 36
Electrical 16 24
Solution: P(Woman) = 0:60, while
P(WomanjElectrical) = 24=40 = 0:60. The events are
independent.