Let us assume the number of text books sold by <span>keller publishing = x
Then
Then </span>number of text books sold by <span>Scholastic books = 4x
The total number of text books sold = 7775
Then
x + 4x = 7775
5x = 7775
x = 1555
Then
The nu</span>mber of text books sold by Scholastic books = 4x
= 4 * 1555
= 6220
I hope the procedure is clear enough for you to understand.
Answer:
z = -12
Step-by-step explanation:
The given system of equations is:
xy/(x + y) = 1 ...........................(1)
xz/(x + z) = 2...........................(2)
yz/(y + z) = 3...........................(3)
From (1): x + y = xy
=> y = xy - x
y = x(y - 1)
x = y/(y - 1).......................................(4)
From (2): 2(x + z) = xz
=> 2x + 2z = xz
2x = xz - 2z
2x = z(x - 2)
z = 2x/(x - 2) ....................................(5)
From (3): 3(y + z) = yz
=> 3y + 3z = yz
3y = yz - 3z
3y = z(y - 3)
z = 3y/(y - 3)....................................(6)
Comparing (5) and (6)
2x/(x - 2) = 3y/(y - 3)
2x(y - 3) = 3y(x - 2)
2xy - 6x = 3xy - 6y
6(y - x) = xy .................................(7)
But from (1): xy = x + y
Using this in (7), we have
6(y - x) = x + y
6y - y - 6x - x = 0
5y - 7x = 0
5y = 7x
x = 5y/7................................................(8)
Using this in (4)
5y/7 = y/(y - 1)
1/(y - 1) = 5/7
(y - 1) = 7/5
y = 1 + 7/5
y = 12/5..........................................(9)
Using this in (8)
x = 5(12/5)/7 = 12/7 .......................(10)
Using (10) in (5)
z = 2x/(x - 2)
z = 2(12/7) ÷ (12/7 - 2)
= 24/7 ÷ -2/7
= 24/7 × (-7/2)
= -24/2 = -12
z = -12.
Answer:
Maridel wants to find out how many of her classmates plan to come to the next football game. There are 800 students in her school. She selects a sample of the population by putting the names of every student into a bag and drawing out 100 names.
Which statement(s) describe her sampling method? Check all that apply.
A) Her method will produce a biased sample.
<u>B) Her method will produce a valid sample.</u>
<u>C) Her method will produce a random sample.</u>
<u>D) Her method will produce a representative sample.</u>
E) Her method will produce an invalid sample.
Step-by-step explanation:
One number is 15 and the other is 16. You get this answer by first finding a factor of 3(15) that when it's subtracted from 31 gives you a factor of 8(16). Then you divide in this case 15 by 3 and get 5 and 16 by 8 and get 2. The reason you divided the numbers is because now you have 5 which is 1/3 of 15 and 2 which is 1/8 of 16. Now that you have your numbers that equal your fractions multiply 5 which is your 1/3 by the 2 from your 2/3 to get 10 which is 2/3 of 15 and 2 which is 1/8 by the 5 from you 5/8 to get 10 which is 5/8 of 16
Answer:
C is the answer they are equal.
Step-by-step explanation:
