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.
I think the answer would be no. We create computers so we can do the problems ourselves. maybe eventually the asnwer will be yes, but for now i think they just solve equations quicker than the average human brain. hope this helps!
Among digits, 10% of 10 digits is a single digit. Any answer choice that suggests more than one digit be used for "yes" is not appropriate. A good choice is ...