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:
Step-by-step explanation:
It's an arithmetic sequence.
The difference is constant.
The explicit formula of an arithmetic sequence:
Substitute:
<em>use distributive property</em>
Answer:
x = 14
Step-by-step explanation:
Step 1: First, Simplify the fraction.
Step 2: Next, Multiply both sides by 7.
4x = 8 × 7
Step 3: Simplify 8 × 7 to 56.
4x = 56
Step 4: Then, Divide both sides by 4.
Step 5: Lastly, Simplify the fraction and you're done!
x = 14
Answer: Have a good day. I’m sorry you have to go through this, my head already hurts and I am just lōoking at it.
So, 4 x 3 is 12, so 4 blades cost 79.74 x 3 (because every turbine has 3 blades each) is 318.96
