# Atomic Mass Calculations: Extra Help and Explanation

this is a thought question where you don't really have to any calculation and it revolves around the idea of relative

## atomic

weight so let's just do a little bit of review for that let's say that we have a type of pickup truck called the rodeo pickup truck the rodeo pickup truck comes in two types the rodeo clown there's kind of a dinky little thing that weighs 5,000 pounds and the rodeo cowboy which is monstrous and weighs 20,000 pounds now what is the average weight
of these two pickup trucks if I said average weight we'd probably do is you would add the two weights together divide by 2 and you get 12,500 pounds which is right in between 5,000 for the clown and 20,000 for the cowboy but what if I told you this what if I said that most people didn't like to drive the clown because they thought it made them look like losers so only 20% of the rodeo pickup trucks on the road were the rodeo clown on the other hand 80% of the rodeo pickups on the road
were the rodeo cowboy because people thought it made them look tough so in that case what is the average weight of all of these pickup trucks right because they're only 20% of the clown and 80% of the cowboy then this average doesn't really seem to make sense because it assumes that we have the same amount of both of these but we have much more of the cowboy than of a clown and the cowboy weighs a lot more in this case we have to calculate what's called a relative or a weighted
average where we take weights of each one of these and multiply it by the percentage that we have of it so 5,000 pounds for the clown times 20% as a decimal plus 20,000 pounds with a cowboy times 80 percent as a decimal and then when we do that we end up with an average that's not right in the middle we end up with an average that's tilted higher closer to the weight of the cowboy and that makes sense because there are many more cowboy pickups on the road our average of these weights
should be closer to the weight of the cowboy