Ratios & Proportions

A proportion is a statement that two ratios are equivalent to each other. Two ratios form a proportion if their cross products are equal.
Do these ratios form a proportion? Tony swims 10 laps in 30 minutes. Write the ratios as fractions. and
The cross products are equal, so the ratios form a proportion. Do these ratios form a proportion? Tony reads a 120page book in 4 hours. Write the ratios as fractions. and
The cross products are not equal, so the ratios do not form a proportion. 