Is the ratio 4.2: 1.5 proportional to the ratio 12.6: 4.5? explain.

Antonio made a scale model of a building. the model's scale is 1 inch to 235 feet and its height is 3.5 inches. what is the exact height of the actual building? enter your answer in the box.

Boris needs to buy plastic spoons. brand a has a box 42 spoons for $2.37. brand b has a box of 72 spoons for $3.57. find the unit price for each brand. then state which brand is the better buy based on the unit price. round your answer to the nearest cent.

Ade and abc are similar. which best explains why the slope of the line between points a and d is the same as the slope between points a and b?