The water level of a lake fell by 1 1/4 in. during a 1 1/2 week long drought what is the average rate at which the water level changed every week

Answer:[tex]\frac{5}{6}[/tex]  inches per weekStep-by-step explanation:This is a very simple ratio problem. Basically,If [tex]1\frac{1}{4}[/tex] inches in  [tex]1\frac{1}{2}[/tex] week, then HOW MANY INCHES (let it be x) in 1 week???We set up two ratios and cross multiply and solve for x:[tex]\frac{1\frac{1}{4}}{1\frac{1}{2}}=\frac{x}{1}\\1\frac{1}{4}*1=1\frac{1}{2}*x\\1\frac{1}{4}=1\frac{1}{2}x\\x=\frac{1\frac{1}{4}}{1\frac{1}{2}}\\x=\frac{\frac{5}{4}}{\frac{3}{2}}\\x=\frac{5}{4}*\frac{2}{3}\\x=\frac{5}{6}[/tex]So average rate at which the water level changed every week is 5/6 inches per week.