# Question: According to Money in the year prior to March 2007

According to Money, in the year prior to March 2007, the average return for firms of the S&P 500 was 13.1%. Assume that the standard deviation of returns was 1.2%. If a random sample of 36 companies in the S&P 500 is selected, what is the probability that their average return for this period will be between 12% and 15%?

## Relevant Questions

An economist wishes to estimate the average family income in a certain population. The population standard deviation is known to be $4,500, and the economist uses a random sample of size n = 225. What is the probability that ...An advertisement for Citicorp Insurance Services, Inc., claims "one person in seven will be hospitalized this year." Suppose you keep track of a random sample of 180 people over an entire year. Assuming Citicorp's ...Your bank sends you a summary statement, giving the average amount of all checks you wrote during the month. You have a record of the amounts of 17 out of the 19 checks you wrote during the month. Using this and the ...The average value of $1.00 in euros in early 2007 was 0.76. If σ = 0.02 and n = 30, find P(0.72 < x̄ < 0.82). Is the sample median a biased estimator of the population mean? Why do we usually prefer the sample mean to the sample median as an estimator for the population mean? If we use the sample median, what must we assume about ...Post your question