The number of music CDs sold weekly by a store follows a normal distribution with a mean of 455 and a standard deviation of 65. Which sentence summarizes this information?

Question

anonymous · Answer

A.

There is an 84% chance that the shop sells more than 390 CDs in a week. 




B.
There is a 34% chance that the shop sells more than 390 CDs in a week.




C.
There is a 34% chance that the shop sells fewer than 390 CDs in a week.




D.
There is a 68% chance that the shop sells fewer than 390 CDs in a week. 




E.
There is a 95% chance that the shop sells more than 390 CDs in a week.

anonymous · Answer

@amistre64 last question :)

amistre64 · Answer

we need to determine how many standard deviations divide into the difference between 390 and the mean

amistre64 · Answer

390 - 455
---------  =  z score
     65

anonymous · Answer

-1?

amistre64 · Answer

correct,  not by applying the empirical rule ...

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