Finding the Fourth Proportional to 156,991.10, 216,649.89 and 85,372.25

Step by Step Solution

1. Step 1: Write the proportion equation
   156,991.10 : 216,649.89 = 85,372.25 : x
2. Step 2: Convert to fraction form
   156,991.10/216,649.89 = 85,372.25/x
3. Step 3: Cross multiply
   156,991.10x = 216,649.89 × 85,372.25
4. Step 4: Simplify right side
   156,991.10x = 18,495,887,488.30
5. Step 5: Solve for x
   x = 18,495,887,488.30/156,991.10
6. Step 6: Final answer
   x = 117,814.88