I am having trouble figuring out the standard deviation of bank a and bank b$.$ Consider two local banks. Bank A has $80$ loans outstanding, each for $$1\mathrm{.}5$ million, that it expects will be repaid today. Each loan has a $7\%$ probability of default, in which case the bank is not repaid anything. The chance of default is independent across all the loans. Bank B has only one loan of $$120$ million outstanding, which it also expects will be repaid today. It also has a $7\%$ probability of not being repaid. Calculate the following:

a$.$ The expected overall payoff of each bank.

b$.$ The standard deviation of the overall payoff of each bank.

a$.$ The expected overall payoff of each bank.

The expected overall payoff of Bank $A$ is $$111\mathrm{.}6$ million. $($Round to two decimal places.$)$

The expected overall payoff of Bank B is $$111\mathrm{.}6$ million. $($Round to two decimal places.$)$

b$.$ The standard deviation of the overall payoff of each bank.

The standard deviation of the overall payoff of Bank $A$ is $ million. $($Round to four decimal places.$)$