Finding the Fourth Proportional to 12,998.57, 19,499.09 and 3,638.61

Step by Step Solution

1. Step 1: Write the proportion equation
   12,998.57 : 19,499.09 = 3,638.61 : x
2. Step 2: Convert to fraction form
   12,998.57/19,499.09 = 3,638.61/x
3. Step 3: Cross multiply
   12,998.57x = 19,499.09 × 3,638.61
4. Step 4: Simplify right side
   12,998.57x = 70,949,565.67
5. Step 5: Solve for x
   x = 70,949,565.67/12,998.57
6. Step 6: Final answer
   x = 5,458.26