Final answer:
To calculate the percentage that the number 4 represents in a 2:4:5 ratio with a total of 220, determine the value of each part of the ratio and then use the part over total formula. The value for B (which is 4) is 80, and therefore, its percentage is 36.36%.
Step-by-step explanation:
To find the percentage that the number 4 represents in the ratio 2:4:5 when the total is 220, we first need to determine the total number of parts in the ratio.
Adding the ratio numbers together, we get 2+4+5 = 11 parts in total.
Now, since B is 4, we divide the total amount, 220, by the number of parts, 11, to find the value of one part: 220 ÷ 11 = 20. Value of B is, therefore, 4 parts times 20, which is 80.
Next, to find the percentage composition of B, we use the formula to calculate percentage:
Percentage = (Part ÷ Total) × 100.
For B, this is (80 ÷ 220) × 100, giving us 36.36%, which is the percentage that the number 4 represents in the total of 220.