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.
30 treadmills : 36 ellipticals
this could be written in a few ways, but i am going to write it as a fraction. since treadmills come first, you put 30/36.
now that you have your fraction you have to find the GCF (greatest common factor) of the two numbers. the GCF is 6, so you have to divide 30 treadmills by 6, and 36 ellipticals by 6.
30/6=5
36/6=6
5/6 or 5:6 is the simplified ratio of treadmills to ellipticals
comment for any questions!!
Answer:
50/18 or 2.77
Step-by-step explanation:
So first u have to make the 3 1/3 and 1 1/5 into improper fractions.
Then, you can do the keep, change, flip thing and then u get 10/3 x 5/6 to get 50/18
Answer:
x&y just cancel out for 7
x and y should both be 3
Step-by-step explanation:
its the best choice
Is that considered two equations?
