Here are returns and standard deviations for four investments.

Return Standard Deviation

Treasury bill: 6.5% 0%

Stock P 8.5% 18%

Stock Q 14% 32%

Stock R 22.5% 26%

Calculate the standard deviations of the following portfolios.

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

B. 50% each in Q and R, assuming the shares have:

1.Perfect Positive Correlation

2. Perfect Negative Correlation

3. No Correlation