Final answer:
The amount of flour missing from the bag is 1/5, which can also be written as a decimal (0.2) and as a percent (20%).
Step-by-step explanation:
If Mia buys a 5 lb bag of flour and it actually weighs 4 lbs, the amount of flour missing from the bag can be represented as a fraction, a decimal, and a percent.
The difference in weight is 1 lb because 5 lbs - 4 lbs equals 1 lb. To express this as a fraction, we divide the missing weight by the total expected weight: 1 lb / 5 lbs = 1/5.
As a decimal, the fraction 1/5 is equivalent to 0.2. To covert this to a percent, we multiply by 100, which gives us 20%.
Therefore, the amount of flour missing from the bag is 1/5, which is equal to 0.2 or 20%.