Finding the Fourth Proportional to 12,890.50, 19,335.86 and 5,099.30

Step by Step Solution

1. Step 1: Write the proportion equation
   12,890.50 : 19,335.86 = 5,099.30 : x
2. Step 2: Convert to fraction form
   12,890.50/19,335.86 = 5,099.30/x
3. Step 3: Cross multiply
   12,890.50x = 19,335.86 × 5,099.30
4. Step 4: Simplify right side
   12,890.50x = 98,599,350.90
5. Step 5: Solve for x
   x = 98,599,350.90/12,890.50
6. Step 6: Final answer
   x = 7,648.99