Why is it that when two positive fractions are multiplied the product is less than the factors ?

Because you are increasing it by a fractional amount.  

examples:  

1/2 times 1/2 means, what is 1/2 of a 1/2? and the answer is 1/4

the highest percentage for deaths in construction from highest to lowest is as follows: falls, struck by objects, electrocution, and caught-in/between. these four are collectively known as fatal four.

in the case of falls, the type that is responsible for the overall highest death in the category is falls from roofs.