For 12, you would do 90=4x+42, and 48=4x, and x=12
for 15, you would do 90=8x+66, and 24=8x, and x=3
for 18, you would do 90=3x+57, and 33=3x, and x=11
If we call the number "x" then:
x*25%=21
x*25/100=21
x=21*4
x=84
Hope this helps. :)
Answer:
For the top table:
[x] | 3.1 | 2.5 | 1.2 | 0.9 | 0.14 | 0.06 | 0.02 |
[y] | 15.5 | 12.5 | 6 | 4.5 | 0.7 | 0.3 | 0.1 |
For the bottom table:
k = 5
[x] | 3.1 | 2.5 | 1.2 | 0.9 | 0.14 | 0.06 | 0.02 |
[y] | 15.5 | 12.5 | 6 | 4.5 | 0.7 | 0.3 | 0.1 |
