A recent book noted that only 22% of investment managers outperform the standard
ID: 3313640 • Letter: A
Question
A recent book noted that only 22% of investment managers outperform the standard indexes, such as the Dow Jones Industrial Average or the NASDAQ, over a five-year period. A sample of 400 investment managers who had graduated from one of the top 10 business programs in the country were followed over a five-year period. A total of 110 of these outperformed the Dow Jones Industrial Average. Let p represent the probability that a random investment manager who graduated from one of the top 10 business programs will outperform the Dow Jones over a five-year period. Reference: Ref 8-3 Based on the results of the sample, a 95% confidence interval for p is: We can assert that p = 0.22 with 100% confidence because only 22% of investment managers outperform the standard indexes. (0.238, 0.312). (0.217, 0.333). (0.231, 0.319).
Explanation / Answer
The statistical software output for this problem is:
One sample proportion summary confidence interval:
p : Proportion of successes
Method: Standard-Wald
95% confidence interval results:
Hence,
95% confidence interval will be:
(0.231, 0.319)
Proportion Count Total Sample Prop. Std. Err. L. Limit U. Limit p 110 400 0.275 0.022325714 0.2312424 0.3187576Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.