If you have a normal distribution of a random variable x,?

If you have a normal distribution of a random variable x, with a mean of 56 and standard deviation of 8: What is the probability that the random variable x will be within plus or minus 1 standard deviation of the mean?








a. 0.682





b. 0.75





c. 0.00

If you have a normal distribution of a random variable x,?
The answer is A,0.682.





The Curve of the Normal is bell-shaped. According to the Empirical Rule, a bell-shaped distribution has 68% of its value within 1 standard deviation, 95% of its value within 2 standard deviation, and practically all values within 3 standard deviations
Reply:If you study statistics for much longer you will quickly recognise that it is (a) because this is such a well known and used result.
Reply:Agreed, it's .682. I suppose the reason this question throws in irrelevant information on the mean and standard deviation is to confuse the new students. :)