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.
It’s d because 2x4x8 = 64
Answer:
28 yd²
Step-by-step explanation:
find the two biggest sides
2x4
8 but there are two sides...
8*2= 16
*16*
now side panels
1x4
4 but there are two
4*2= 8
*8*
top and bottom panels
2x1
2 but there are two
2*2= 4
*4*
add them up
16 + 8 + 4= 28
check the picture below.
recall that a full circle has 360°.
