Finding the Fourth Proportional to 12,847.56, 17,730.95 and 7,812.15

Step by Step Solution

1. Step 1: Write the proportion equation
   12,847.56 : 17,730.95 = 7,812.15 : x
2. Step 2: Convert to fraction form
   12,847.56/17,730.95 = 7,812.15/x
3. Step 3: Cross multiply
   12,847.56x = 17,730.95 × 7,812.15
4. Step 4: Simplify right side
   12,847.56x = 138,516,779.43
5. Step 5: Solve for x
   x = 138,516,779.43/12,847.56
6. Step 6: Final answer
   x = 10,781.56