Since the 5 hits can be any of the 7 attempts, we first need to calculate a combination of 7 choose 5.
The formula for a combination of n choose p is:
So we have:
Now, if the probability of hitting is 0.28, the probability of missing is 1 - 0.28 = 0.72
Then, for the final probability, we can use the formula:
So the probability is 0.0187.