These are the returns and standard deviations of four investments.

	Give back	Standard deviation
treasure letters	6%	0%
P-shares	10	14
Q-shares	14.5	28
R-shares	21	26

Calculate the standard deviations of the following portfolios.

a.	50% in Treasury bills, 50% in P shares.

Standard deviation

%

b.	50% each in Q and R, assuming the shares have: (Do not round intermediate calculations. Round your answers to 1 decimal place.)

	Standard deviation
Perfect positive correlation	%
perfect negative correlation	%
No correlation	%