If the base is square, and the perimeter is 14.5, that means that each side of the base is 14.5/4=3.625. Since we now know the length and the width, as well as the height which is 16.8, we plug into the formula . So, plug in the details Your answer will be 73.6 cm^3
The formula to calculate standard deviation from probability is \sqrt(n*p*(1-p)). n is the sample size, and 200 in this case (number of putts for practice). p is 80% or 0.8, the probability that he can make it. So the standard deviation is \sqrt(200*0.8*(1-0.8)=\sqrt(200*0.8*0.2)=\sqrt(16)=4.