Finding the Fourth Proportional to 31,189.10, 43,006.91 and 21,100.05

Step by Step Solution

1. Step 1: Write the proportion equation
   31,189.10 : 43,006.91 = 21,100.05 : x
2. Step 2: Convert to fraction form
   31,189.10/43,006.91 = 21,100.05/x
3. Step 3: Cross multiply
   31,189.10x = 43,006.91 × 21,100.05
4. Step 4: Simplify right side
   31,189.10x = 907,447,845.85
5. Step 5: Solve for x
   x = 907,447,845.85/31,189.10
6. Step 6: Final answer
   x = 29,095.04