In designing an experiment involving a treatment applied to 4 test subjects, researchers plan to use a simple random sample of 4 subjects selected from a pool of 31 available subjects. (Recall that with a simple random sample, all samples of the same size have the same chance of being selected.) Answer the question below. What is the probability of each simple random sample in thiscase?

The probability is  

Step-by-step explanation:

From the question we are told that

     The population size is  N =  31

      The sample size  n =  4  

Generally the number of way by which the n  can be selected from N is mathematically represented as

=>      

=>      

=>        

=>        

The number of ways of selecting a particular sample size is  is  

Therefore the probability of each simple random sample in this case is mathematically evaluated as