Finding the Fourth Proportional to 30,531.31, 42,112.17 and 21,475.88

Step by Step Solution

1. Step 1: Write the proportion equation
   30,531.31 : 42,112.17 = 21,475.88 : x
2. Step 2: Convert to fraction form
   30,531.31/42,112.17 = 21,475.88/x
3. Step 3: Cross multiply
   30,531.31x = 42,112.17 × 21,475.88
4. Step 4: Simplify right side
   30,531.31x = 904,395,909.46
5. Step 5: Solve for x
   x = 904,395,909.46/30,531.31
6. Step 6: Final answer
   x = 29,621.92