Finding the Fourth Proportional to 21,047.12, 31,530.18 and 13,152.74

Step by Step Solution

1. Step 1: Write the proportion equation
   21,047.12 : 31,530.18 = 13,152.74 : x
2. Step 2: Convert to fraction form
   21,047.12/31,530.18 = 13,152.74/x
3. Step 3: Cross multiply
   21,047.12x = 31,530.18 × 13,152.74
4. Step 4: Simplify right side
   21,047.12x = 414,708,259.69
5. Step 5: Solve for x
   x = 414,708,259.69/21,047.12
6. Step 6: Final answer
   x = 19,703.80