Finding the Fourth Proportional to 866.72, 1,300.78 and 456.10

Step by Step Solution

1. Step 1: Write the proportion equation
   866.72 : 1,300.78 = 456.10 : x
2. Step 2: Convert to fraction form
   866.72/1,300.78 = 456.10/x
3. Step 3: Cross multiply
   866.72x = 1,300.78 × 456.10
4. Step 4: Simplify right side
   866.72x = 593,285.76
5. Step 5: Solve for x
   x = 593,285.76/866.72
6. Step 6: Final answer
   x = 684.52