There are 82% regular treadmill users = 82% of 1000 = 820 owners. This leaves us with 180 non-users.

Now consider the regular users. 63% lost some weight. So how much is that? 63% of 820 = 516.6

Now for the non-users, 78% have not lost weight…meaning that 22% have lost weight. This number os 22% of 180 = 39.6

So the total number of weight loss ppl = 516.6 + 39.6 = 556.2

Therefore, the probability that a treadmill owner selected at random has lost some weight = 556.2/1000 = 0.5562 = 55.62%