Finding the Fourth Proportional to 21,150.68, 31,749.08 and 12,275.72

Step by Step Solution

1. Step 1: Write the proportion equation
   21,150.68 : 31,749.08 = 12,275.72 : x
2. Step 2: Convert to fraction form
   21,150.68/31,749.08 = 12,275.72/x
3. Step 3: Cross multiply
   21,150.68x = 31,749.08 × 12,275.72
4. Step 4: Simplify right side
   21,150.68x = 389,742,816.34
5. Step 5: Solve for x
   x = 389,742,816.34/21,150.68
6. Step 6: Final answer
   x = 18,426.96