Question 3 Speculate.com is an internet trading company. The company is worried about the continual market slide; it seems to have resulted in a significant decline in both the total number of trades Speculate.com executes and the number of customers who actively trade on Speculate.com. (a) According to the results of a recent survey among 150 randomly selected Speculate. com customers, the average return on $1 invested among the 150 respondents was 96 cents (they lost 4 cents) with a sample variance of (25 cents). Based on the survey results, how confident can you be that Speculate.com customers are losing money on average?' (6 points) (b) A Speculate.com customer is considered "active" if she executes at least one trade per day. September 2003 records indicate that 20% of customers were "active" and that one-quarter of "active" customers outperformed S&P 500 index during that period. On the other hand, one-third of the "nonactive" customers outperformed S&P 500 index during that period. What percentage of customers who outperformed S&P 500 index in September 2003 were "active" customers in that month? (7 points)