Finding the Fourth Proportional to 13,176.72, 18,180.90 and 7,870.50

Step by Step Solution

1. Step 1: Write the proportion equation
   13,176.72 : 18,180.90 = 7,870.50 : x
2. Step 2: Convert to fraction form
   13,176.72/18,180.90 = 7,870.50/x
3. Step 3: Cross multiply
   13,176.72x = 18,180.90 × 7,870.50
4. Step 4: Simplify right side
   13,176.72x = 143,092,773.45
5. Step 5: Solve for x
   x = 143,092,773.45/13,176.72
6. Step 6: Final answer
   x = 10,859.51