The following table presents forecasted returns for three companies under various potential states of the economy:

State	Probability	Stock X	Stock Y	Stock Z
Above Average	10%	38.2%	27.3%	40.7%
Average	45%	16.7%	8.6%	9.3%
Below Average	30%	-1.2%	-4.0%	-7.0%
Recession	15%	-10.2%	-6.0%	-15.5%
Weight		55%	30%	15%

What is the standard deviation on a portfolio of these three companies constructed according to the weights given in the table? (Report answer in percentage terms and round to 2 decimal places. Do not round intermediate calculations).