The stock market in Mexico reported weak returns in 2011. The population of stocks earned a mean return of -3.8% in 2011. (Data extracted from USA Today, January 3, 2012, p. 2B.) Assume that the returns for stocks on the Mexican stock market were distributed as a normal random variable, with a mean of -3.8 and a standard deviation of 20. If you selected a random sample of 16 stocks from this population, what is the probability that the sample would have a mean return.
a. Less than 0?
b. Between -10 and 10?
c. Greater than 10?