Finding the Fourth Proportional to 21,742.31, 30,004.50 and 12,312.71

Step by Step Solution

1. Step 1: Write the proportion equation
   21,742.31 : 30,004.50 = 12,312.71 : x
2. Step 2: Convert to fraction form
   21,742.31/30,004.50 = 12,312.71/x
3. Step 3: Cross multiply
   21,742.31x = 30,004.50 × 12,312.71
4. Step 4: Simplify right side
   21,742.31x = 369,436,707.20
5. Step 5: Solve for x
   x = 369,436,707.20/21,742.31
6. Step 6: Final answer
   x = 16,991.60