A particular camera is sold at an average price of $190, with a standard deviation of $12. In a sample of 50 randomly selected stores, what is the probability that the sample mean falls within $4 (i.e., between $186 and $194) of the population mean?

Select one:

a. 0.4909

b. 0.9913

c. 0.9816

d. 0.9818

e. 0.9825