Final answer:
Babies gain an average of 194 ounces in their first year, calculated by converting the average newborn weight of 7.5 pounds to 120 ounces and the 1 year old weight of 19 pounds 10 ounces to 314 ounces, then subtracting the newborn weight from the 1 year old weight.
Step-by-step explanation:
To calculate how many ounces babies gain in their first year on average, we must first convert the weights into a consistent unit. Since we have the weights in pounds and ounces, we will convert everything to ounces. There are 16 ounces in a pound.
The average weight for a newborn baby is 7.5 lb, which converts to 120 ounces (7.5 lb x 16 oz/lb).
The average weight for a 1 year old is 19 pounds and 10 ounces. This is 314 ounces in total (19 lb x 16 oz/lb + 10 oz).
Now, we subtract the newborn's weight in ounces from the 1-year-old's weight in ounces to find the average weight gain:
314 ounces (1-year-old's weight) - 120 ounces (newborn's weight) = 194 ounces.
So, on average, babies gain 194 ounces in their first year.