Finding the Fourth Proportional to 21,036.32, 31,533.18 and 13,645.47

Step by Step Solution

1. Step 1: Write the proportion equation
   21,036.32 : 31,533.18 = 13,645.47 : x
2. Step 2: Convert to fraction form
   21,036.32/31,533.18 = 13,645.47/x
3. Step 3: Cross multiply
   21,036.32x = 31,533.18 × 13,645.47
4. Step 4: Simplify right side
   21,036.32x = 430,285,061.69
5. Step 5: Solve for x
   x = 430,285,061.69/21,036.32
6. Step 6: Final answer
   x = 20,454.39