Finding the Fourth Proportional to 153,180.72, 211,419.72 and 99,390.24

Step by Step Solution

1. Step 1: Write the proportion equation
   153,180.72 : 211,419.72 = 99,390.24 : x
2. Step 2: Convert to fraction form
   153,180.72/211,419.72 = 99,390.24/x
3. Step 3: Cross multiply
   153,180.72x = 211,419.72 × 99,390.24
4. Step 4: Simplify right side
   153,180.72x = 21,013,056,711.53
5. Step 5: Solve for x
   x = 21,013,056,711.53/153,180.72
6. Step 6: Final answer
   x = 137,178.21