Need help finding standard deviation, average return, and coefficient of variation please???

Question

The market portfolio is assumed to be composed of two securities, Investment X and Y as shown below. Determine based on the information given the Average return, Standard Deviation and Coefficient of Variation. Which is the better investment?

Year Return X Return Y

1997 16.5% 17.5%

1998 14.2% 13.2%

1999 13.5% 14.5%

2000 16.1% 15.1%

2001 12.2% 13.2%

2002 11.5% 10.5%

A portfolio consists of five securities with following Beta and Proportions:

What is the Beta of the portfolio?

Asset Beta Proportions

1 1.35 .1

2 1.12 .2

3 1.67 .3

4 1.04 .2

5 1.55 .2

Something just doesn't work out right when i try the formulas.

Answer 1

Question 1)

for X, the average return is 14.0%; the variance is 0.20%; and the standard deviation, which is teh square root of the variance is 0.03%.

for Y, the average return is 14.3%; the variance is 0.27%; and the standard deviation, which is teh square root of the variance is 0.05%

For question 2, the weighted avg beta of the portfolio is 1.378.

Question 1 was answered by the following steps:

1) find the average return

2) take each return minus the average return

3) square each result

4) get the total sum of teh squared results obtained in #3.

5) your variance is the square root of step #4 / the number of data points, in this case 6. .

6) your standard deviation is teh square root of the number you get in step #5.

for question two you simply multiply the two columns together.  then total the results.

here's the google spreadsheet i used to calculate the answers for Y, and the port. beta.    not sure if the link will actually work though b/c thisis the first time i've used google spreadsheets.

http://spreadsheets.google.com/ccc?key=p...