Decrease because you taking something off of something
For every 3 girls, there are 4 boys. if there are nine girls, that expands to three extra boys, because for every three theres an extra one. so there are 12 boys (9+3.) the final ratio, boys to girls, is 12:9.
Answer:

Step-by-step explanation:
x = 0.369369369...
10x = 3.69369369...
100x = 36.9369369...
1000x = 369.369369...
1000x - x = 369
999x = 369

Answer:
16%
Step-by-step explanation:
add all of them together (total=18) and divide 3 by the total
You will get 0.16 and you turn it into a percentage by moving the decimal two places to the right