Weights in kilograms of boys at the start of 1st grade are approximately normal with mean 25, standard deviation 5. Based on the z-score for each of the following weights, use the 68-95-99.7 Rule to estimate the probability of being this light or lighter (if below average), or the probability of being this heavy or heavier (if above average).
a. 31.7 kilograms
b. 47 kilograms
c. 24 kilograms