Jul

14

The probability that a treadmill owner selected at random has lost some weight

Filed Under Treadmills 

In a survey of 1000 treadmill owners, 82% of them use their treadmill regularly. Of those who use their treadmill regularly, 63% have lost some weight and 78% of those who do not use their treadmill regularly have not lost some weight.

What is the probability that a treadmill owner selected at random has lost some weight?

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Comments

One Response to “The probability that a treadmill owner selected at random has lost some weight”

  1. The Elder God on June 25th, 2009 3:42 pm

    So we have 2 categories – Regular treadmill users and Non-treadmill users.

    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%