Paul plans to make some peanut butter sandwiches. He will put the same amount of peanut butter on each sandwich. Therefore, the amount of peanut butter that he needs depends on the number of sandwiches he plans to make. For example, to make 3 sandwiches, Paul needs 412 tablespoons of peanut butter. If he were to make 7 sandwiches, he would need 1012 tablespoons of peanut butter. Calculate the constant of proportionality. Record the answer as a decimal number to the nearest tenth.