Finding the Fourth Proportional to 13,158.05, 19,730.67 and 4,390

Step by Step Solution

1. Step 1: Write the proportion equation
   13,158.05 : 19,730.67 = 4,390 : x
2. Step 2: Convert to fraction form
   13,158.05/19,730.67 = 4,390/x
3. Step 3: Cross multiply
   13,158.05x = 19,730.67 × 4,390
4. Step 4: Simplify right side
   13,158.05x = 86,617,641.30
5. Step 5: Solve for x
   x = 86,617,641.30/13,158.05
6. Step 6: Final answer
   x = 6,582.86