Finding the Fourth Proportional to 1,406.34, 2,109.78 and 540.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,406.34 : 2,109.78 = 540.72 : x
2. Step 2: Convert to fraction form
   1,406.34/2,109.78 = 540.72/x
3. Step 3: Cross multiply
   1,406.34x = 2,109.78 × 540.72
4. Step 4: Simplify right side
   1,406.34x = 1,140,800.24
5. Step 5: Solve for x
   x = 1,140,800.24/1,406.34
6. Step 6: Final answer
   x = 811.18