Finding the Fourth Proportional to 21,003.32, 28,978.36 and 12,498.63

Step by Step Solution

1. Step 1: Write the proportion equation
   21,003.32 : 28,978.36 = 12,498.63 : x
2. Step 2: Convert to fraction form
   21,003.32/28,978.36 = 12,498.63/x
3. Step 3: Cross multiply
   21,003.32x = 28,978.36 × 12,498.63
4. Step 4: Simplify right side
   21,003.32x = 362,189,799.65
5. Step 5: Solve for x
   x = 362,189,799.65/21,003.32
6. Step 6: Final answer
   x = 17,244.41