For each histogram bar, we start by multiplying the central x-value to the corresponding bar height. Each of these products corresponds to the sum of all values falling within each bar. Summing all products gives us the total sum of all values, and dividing it by the number of observations yields the mean.
I take it each student is going to make a block. She has 25 + 28 students all together which is 53 students total Each one requires 512 magnetic blocks
