Description
A sample of 500 large companies showed that 130 of them offer free health fitness centers to their employees on the company premises. If one company is selected at random from this sample, what is the probablilty that this company offer's a free health fitness center to its employees on the company premises? What is the probability that this company does not offer a free health fitness center to its employees on the company premises? Do theses 2 probabilities add up to 1.0? why?
Explanation & Answer
So, the probability that the company DOES offer a free health fitness center is
130/500 = 13/50 = 0.26
The probability that it does NOT offer a free health fitness center is 370/500 = 0.74 because if 130 offer it then 370 do not since there are a total of 500 companies in the sample.
The sum of the two probabilities are 0.26 + 0.76 = 1.0 YES they do add up to 1.0
That's because there are only two possibilities, either the company offers a free health fitness center or it does not. The sum of all possibilities must be 100% or 1.