This is a problem in "binomial probability." Either the archer hits his target or he does not. This experiment is performed 5 times (so that n=5), and the probability that the archer will hit the target is 0.7 (so that p=0.7).
We need to find the binomial probability that x=3 when the possible outcomes are {0, 1, 2, 3, 4, 5}.
You could use a table of binomial probabilities to evaluate the following:
P(5, 0.7, 3).
Alternatively, you could use a TI-83 or TI-84 calculator and its built-in "binompdf( " function.
I evaluated binompdf(5,0.7,3) and obtained the result 0.309.
