Use the datasetBerkshire.csv(https://www.dropbox.com/s/plo0hc4t008s0xq/Berkshire.csv?dl=0)

with the following variables. All returns reported as a decimal (as opposed to a percentage).

Sample Period: From30thNov 1976to31stDec 2005 (Inclusive)

• Column (1):Date, Calendar Date
• Column (2):BRKret, Berkshire Hathaway's monthly return
• Column (3):MKT, the return on the aggregate stock market
• Column (4):RF, the risk free rate of return

What is the standard deviation for Berkshire Hathaway's returns over the sample period?

Note:Rememberto filterthe datafor the sample period, before solving the problem.

A:7.55%

B: 7.61%

C: 7.42%

D: 7.37%