We can write an equation to solve this problem as:
#p_n = p_o + (p_o * i)# Where:
#p_n# is the new price of the product, what we are solving for in this problem.
#P_o# is the old price of the product. $4.30 per foot or #($4.30)/"ft"# in this problem.
#i# is the price increase percent. 10% for this problem. "Percent" or "%" means "out of 100" or "per 100", Therefore 10% can be written as #10/100#.
Substituting and solving for #p_n# gives:
#p_n = ($4.30)/"ft" + (($4.30)/"ft" * 10/100)#
#p_n = ($4.30)/"ft" + ($43.00)/(100"ft")#
#p_n = ($4.30)/"ft" + ($0.43)/"ft"#
#p_n = ($4.73)/"ft"#
The new price is $4.73 per foot.