Question

Would you rather take an exam that typically has an mean of 80 with a standard deviation of 3 or an exam with a mean of 80 with a standard deviation of 15? why?

Answer 1

I would take the 80% with a standard deviation (σ) of 3%. This way, 68% of the time, I would get between 77% and 83%, and 95% of the time I get between 74% and 86%.

If you are a risk taker and take σ=15%, then there is a 9.12% that you'll get below 60%.

Check my calculations using a normal distribution table, or from the link below:
http://www.mathsisfun.com/data/standard-normal-distribution-table.html

Answer 2

Thank You