Finding the Fourth Proportional to 1,008.72, 1,511.78 and 453.02

Step by Step Solution

1. Step 1: Write the proportion equation
   1,008.72 : 1,511.78 = 453.02 : x
2. Step 2: Convert to fraction form
   1,008.72/1,511.78 = 453.02/x
3. Step 3: Cross multiply
   1,008.72x = 1,511.78 × 453.02
4. Step 4: Simplify right side
   1,008.72x = 684,864.31
5. Step 5: Solve for x
   x = 684,864.31/1,008.72
6. Step 6: Final answer
   x = 678.94