Assume that your cousin holds just one stock, Eastman Chemical Bonding (ECB), which he thinks has very little risk. You agree that the stock is relatively safe, but you want to demonstrate that his risk would be even lower if he were more diversified. You obtain the following returns data for Wilder's Creations and Buildings (WCB). Both companies have had less variability than most other stocks over the past 5 years. Using the standard deviation of returns, by how much would your cousin's risk have been reduced if he had held a portfolio consisting of 70% in ECB and the remainder in WCB?

	Year	ECB	WCB
	2007	40.00%	40.00%
	2008	-10.00%	15.00%
	2009	35.00%	-5.00%
	2010	-5.00%	-10.00%
	2011	15.00%	35.00%

*Show your computations and/or excel functions you used in your solution.