A line on a graph shows a proportional relationship between the amount of almonds, x, in grams and the total calories y. Two points on the graph are located at (50, 287.5) and (70, 402.5). What is the unit rate for the number of calories per gram of almonds? 1.64 calories per gram 2.3 calories per gram 5.75 calories per gram 17.25 calories per gram