Finding the probability of doubling and tripling

Assume that the returns from an asset are normally distributed. The average annual return for this asset over a specific period was 16.9 percent and the standard deviation of those returns in this period was 43.56 percent. What is the approximate probability that your money will double in value in a single year? (Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.) Probability of doubling % What about triple in value? (Do not round intermediate calculations. Enter your answer as a percent rounded to 6 decimal places, e.g., 32.161616.) Probability of tripling %