Finding the Fourth Proportional to 12,689.84, 17,511.88 and 7,100.80

Step by Step Solution

1. Step 1: Write the proportion equation
   12,689.84 : 17,511.88 = 7,100.80 : x
2. Step 2: Convert to fraction form
   12,689.84/17,511.88 = 7,100.80/x
3. Step 3: Cross multiply
   12,689.84x = 17,511.88 × 7,100.80
4. Step 4: Simplify right side
   12,689.84x = 124,348,357.50
5. Step 5: Solve for x
   x = 124,348,357.50/12,689.84
6. Step 6: Final answer
   x = 9,799.05