The sign of each Y coordinate changed
<span>f(x<0)=-f(x>0)=-x^2+5x+12
When x>0, x^2-5x-12=12, x=8, y=12
Therefore, f(x)=12 goes through point (8,12).</span>
After 2.0 years, the 4.0 mg sample decays to 2.0 mg.
After another 2.0 years (total 4.0 years), the 2.0 mg sample decays to 1.0 mg.
And after another 2.0 years (total 6.0 years), the 1.0 mg sample decays to 0.50 mg.
So it takes 6.0 years for 4.0 mg to decay to 0.50 mg.
1 3 6 concrete ratio
Concrete
Proportions by Cement No. of 50 kg Sand to total aggregate
1:3:6 4.0 31
1:4:5 4.0 41
1:3:5 4.4 35
1:4:4 4.5 47
She should randomly select campers period, because she wants to estimate the percentage of "campers that ride once a week" and not for example what percentage of campers who ride that ride once a week...
