this question is unambiguous.
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:
d. 15 square yard
Step-by-step explanation:
Answer: choice C) -15x^4y
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Explanation:
The coefficients are -3 and 5. They are the numbers to the left of the variable terms
Multiply the coefficients to get -3*5 = -15. So -15 is the coefficient in the answer
Multiply the x terms to get x^3 times x = x^(3+1) = x^4. Notice the exponents are being added
Do the same for the y terms as well: y^2 times y^(-1) = y^(2+(-1)) = y^(2-1) = y^1 = y
So we have a final coefficient of -15, the x terms simplify to x^4 and the y terms simplify to just y
Put this all together and we end up with -15x^4y which is what choice C is showing
Written just as an expression it would be:
15-5(p-6)
