Step-by-step explanation: First, because it is easier this way, you make the fractions into decimals. It will look like this: 4/5= 0.8, and 4 1/2= 4.5. Then, you just multiply the numbers. Using a calculator is easiest.
The relative frequency is the frequency of the item divided by the total number of all items. The total number of all items here is: 50 + 40 + 90 +20 = 200.