Here are returns and standard deviations for four investments.

	Return	Standard Deviation
Treasury bills	6%	0%
Stock P	10	14
Stock Q	14.5	28
Stock R	21	26

Calculate the standard deviations of the following portfolios.

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

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	%