Finding the Fourth Proportional to 111,215.76, 153,428.61 and 87,411.61

Step by Step Solution

1. Step 1: Write the proportion equation
   111,215.76 : 153,428.61 = 87,411.61 : x
2. Step 2: Convert to fraction form
   111,215.76/153,428.61 = 87,411.61/x
3. Step 3: Cross multiply
   111,215.76x = 153,428.61 × 87,411.61
4. Step 4: Simplify right side
   111,215.76x = 13,411,441,820.16
5. Step 5: Solve for x
   x = 13,411,441,820.16/111,215.76
6. Step 6: Final answer
   x = 120,589.40