The table below shows the one-year return distribution of Startup Inc.

Probability	25%	20%	20%	10%	?%
Return	-90%	-75%	-50%	-25%	1000%

a. Calculate the expected return.

b. Calculate the standard deviation of the return.

c. Replace the expected return of 1000% in the last column in the table above with the expected return value that minimizes the standard deviation of the returns.

a. The expected return is ______%. (round to one decimal)

b. The standard deviation of the return is ________%. (round to one decimal)

c. The value of expected return in last column which minimizes the standard deviation of the returns is ________%. (round to one decimal. If negative, enter a minus sign "-".)