1) You add 72+89 which you get 161 and you divide by two and you get 80.5 2) you do the same thing 72+89+90=251 And you divide by three and you get ≈83.66
You are trying to figure out 1/6 of her weight. Since her weight is 19 pounds, you would put it over one to create a fraction and times is by 1/6 which would give you 19/6.
