In a normal distribution, 68% of the scores lie within
one standard deviation of the mean. If the SAT scores of
all the high school juniors in Center City followed a normal
distribution with a mean of 500 and a standard deviation of 100,
and if 10,200 students scored between 400 and 500,
approximately how many students scored above 600?
(A)2,400
(B)4,800
(C)5,100
(D)7,200
(E)9,600
答案(B)，但不知道怎麼算，
麻煩板上大大解惑，謝謝!