Average (mean) = (sum of all the data) / (# of data)
sum of all the data = (average)(# of data)
Thus for 100 students with an average of 93,
sum of all data = (93)(100) = 9300
and for 300 students with an average of 75,
sum of all data = (75)(300) = 22500
Therefore you would expect the overall average to be
(9300 + 22500) / (100 + 300) = 79.5 %
Now if there are x # of advanced students and y # of regular students, then
x + y = 90 (total # of students) and 93x + 75y = 87(x + y) (overall average)
The second equation can be simplified to x - 2y = 0
Subtracting the two equations yields
x = 60 and y = 90
Therefore you would need 60 advanced and 30 regular students.
If you put 7% into a decimal it would be 0.07
Answer:
3/10
Step-by-step explanation:
Just multiply all of the numerators (top numbers) and then multiple all of the denominators (bottom numbers)
2/3x3/4x3/5 would be 18/60 Then take any number that is a factor to both 18 and 60 and divide both numbers by that factor. I could use 2 or 3 or 6 because both 18 and 60 is divisible by any of these numbers. I will choose 3. I will divide the top and bottom of 18/60 by 3 to get 6/20, now I will divide the top and bottom of that number by 2 to get 3/10
2 hundreds be cause there are 2, and you are trying to find hundreths so take the first number
