The time required to finish a test in normally distributed with a mean of 40 minutes and a standard deviation of 8 minutes. What is the probability that a student chosen at random will finish the test in more than 56 minutes?

84%

2%

34%

16%

Question

The time required to finish a test in normally distributed with a mean of 40 minutes and a standard deviation of 8 minutes. What is the probability that a student chosen at random will finish the test in more than 56 minutes?
		
84%
		
2%
		
34%
		
16%

kropot72 · Answer

This can be solved by using the 'Empirical Rule' for a Normal Distribution. You can find the necessary explanation here: http://en.wikipedia.org/wiki/68%E2%80%9395%E2%80%9399.7_rule