Covariance of returns is zero

In 2001, a portfolio with 6 stocks had the following total return rates in percentages:27.98%, 44.94%,
54.53%, -52.68%, 10.21%, 0.50%. The average return rate for this portfolio was 4.92% and the standard deviation was 37.66%. How confident are you that the return rates will fall within -51.57% and 61.41%?

Which type of preferred shares is the least risky?

Which of the following are problems that an effective corporate governance system would mitigate or eliminate?
I). Proxy voting is not permitted.
II). Board Members are unable to conduct in-depth evaluations of the issues affecting the Company's business.
III). A company requires a simple two-thirds vote for passing a Shareowner resolution and a simple majority vote to pass Board-sponsored initiatives.
IV). The only way for Shareowners to submit resolutions to consider specific issues is at the Company's annual general meeting.

During an economic boom, the AD/AS model indicates that the real interest rate will ____ and real wage rates will ____.