Finding the Fourth Proportional to 21,038.42, 31,580.37 and 18,713.31

Step by Step Solution

1. Step 1: Write the proportion equation
   21,038.42 : 31,580.37 = 18,713.31 : x
2. Step 2: Convert to fraction form
   21,038.42/31,580.37 = 18,713.31/x
3. Step 3: Cross multiply
   21,038.42x = 31,580.37 × 18,713.31
4. Step 4: Simplify right side
   21,038.42x = 590,973,253.72
5. Step 5: Solve for x
   x = 590,973,253.72/21,038.42
6. Step 6: Final answer
   x = 28,090.20