Finding the Fourth Proportional to 21,131.68, 29,162.64 and 12,748

Step by Step Solution

1. Step 1: Write the proportion equation
   21,131.68 : 29,162.64 = 12,748 : x
2. Step 2: Convert to fraction form
   21,131.68/29,162.64 = 12,748/x
3. Step 3: Cross multiply
   21,131.68x = 29,162.64 × 12,748
4. Step 4: Simplify right side
   21,131.68x = 371,765,334.72
5. Step 5: Solve for x
   x = 371,765,334.72/21,131.68
6. Step 6: Final answer
   x = 17,592.80