kuristar wrote:

A certain characteristic in a large population has a distribution that is symmetric about the mean M. If 68 percent of the distribution lies within one standard deviation D of the mean, what percent of the distribution is less than M+D?

a. 16%

b. 32%

c. 48%

d. 84%

e. 92%

Please show your work.

using standard normal distribution that would be 84%

as it is expected that 68% of the population is within 1 standard deviation, and if is symetric 34% would be above the mean that is 0.5

so add 34%+50% = 84%