calulating multiple % rates

ok here is what I need help with , a formula for:

if F is less than 75% then G needs to be $0
If F is between 75 and 85% then G needs to be $15
If F is between 85 and 99% then G needs to be $30
If F is 100% or greater then G need to be $100

So I've done single percents =IF(E7>F7,100,0) Basically they sell 100 percent of goal (E being sales , F being sales goal) get $100 bonus , so G would be $100 bonus they earned
But have never done one that has different bonus levels like this.