The physics scores of 200 students follow a normal distribution with a mean of 75 and a standard deviation of 7. Which conclusion is best supported by this information?

Question

anonymous · Answer

A. About 32 students have a score higher than 89. 
B. About 4 students have a score higher than 89.
C. About 100 students have a score higher than 89
D. About 4 students have a score lower than 89.
E. About 32 students have a score lower than 89

anonymous · Answer

@amistre64

amistre64 · Answer

what is 89 - 75 .... divided by 7?

amistre64 · Answer

i get 14/7 = 2

so by the empirical rule,  89 is 2 standard deviation from the mean given us a 95%

adding in the 2.5 % on the left tell us that:

97.7% are under 89,  and 2.5% are over 89

amistre64 · Answer

97.5% that is

anonymous · Answer

1 second

anonymous · Answer

let me reread that

anonymous · Answer

how did you get 97.7 if you add2.5

amistre64 · Answer

recall the empirical rule, it defines a spread about the mean

2 sds is equal to 95%|dw:1373309361140:dw|

that leaves us with 5% split between the tails:  5/2 = 2.5