Question 114405
x = pounds of oats to be added to the mixture
(pounds of oats already in mixture) + (pounds of oats to be added)
divided by 
(pounds of mixture + pounds of oats to be added)
equals .86
{{{(.32*21 + x) / (21 + x) = .86}}}
{{{6.72 + x = .86(21 + x)}}}
{{{6.72 + x = 18.06 + .86x}}}
{{{x - .86x = 18.06 - 6.72}}}
{{{.14x = 11.34}}}
{{{x = 81}}}
81 pounds of oats should be added to the mixture
check:
{{{(.32*21 + x) / (21 + x) = .86}}}
{{{(.32*21 + 81) / (21 + 81) = .86}}}
{{{(6.72 + 81) / 102 = .86}}}
{{{87.72 / 102 = .86}}}
{{{.86 = .86}}}
OK