The difference between 3 and 7 is 4. The difference between 180 and 368 is 188. So every 4 years it increases 188 cm. A rate change of 4/188 simplify this fraction to be 1/47 so every 1 year it increases by 47 cm. So 7 to 10 years is 3 years, so 47 x 3 = 141cm.