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.
Answer:
2.3 hours, or 2 hours & 18 minutes
Step-by-step explanation:
we are trying to find h when d is 56.68, so I replaced d with 56.68
subtract 0.1 from both sides
divide both sides by 24.6
Answer:
B -1/2
Step-by-step explanation:
4x+8y = 11
We need to get the equation in the slope intercept form
y = mx+b where m is the slope and b is the y intercept
Subtract 4x from each side
4x-4x+8y = -4x+11
8y = -4x+11
Divide by 8
8y/8 = -4x/8 +11/8
y = -1/2x +11/8
The slope is -1/2 and the y intercept is 11/8
A^2 + 16^2 = 20^2
(Third one)
