please the answear from 4to7

3. The average rate of return on investments in large stocks has outpaced that on investments in T-bills by almost 7% since 1926 . Why, then, anyone invest in Tbills? 4. Why are money market securities sometimes referred to as "cash equivalents"? 5. Which financial asset class is more risky, common stocks, or corporate bonds? Explain your answer. 6. What is margin trading? To engage into a margin trading what would be your expectation about the future price of the stock? Explain the steps you need to take to make a margin trading? 7. What is short selling? To engage into a short selling what would be your expectation about the future price of the stock? Explain the steps you need to take to make a short selling