Okay so we have to figure out what percentage passed first let’s add all the percentages
25%+15%= 40%
Now subtract that from 100%
100%-40%= 60%
So 60% of the class passed
Now let’s use x to represent the total number of people on the class
x•0.6= 24
Now solve for x
x= 40
There are 40 people in the class we figure this out my converting 60% to 0.6 and multiplying it by 40 and getting 24 which is correct
C sometimes, It seems to be completely arbitrary when one must subtract the z-score table value from 1. ... So that's great if you want the left tail of a distribution, but if you want a right tail then you need to calculate the left tail and subtract it from 1 (which is the area of the entire standard normal curve).
