The Post Office Has Established a Record in a Major

Multiple Choice

The Post Office has established a record in a major Midwestern city for delivering 90% of its local mail the next working day when there are 8 local letters mailed .What is the probability that the number of delivered will be within 2 standard deviations of the mean?

A) .9950
B) .9619
C) .8131
D) .9996