Finding the Fourth Proportional to 8,721.30, 13,081.89 and 2,878.38

Step by Step Solution

1. Step 1: Write the proportion equation
   8,721.30 : 13,081.89 = 2,878.38 : x
2. Step 2: Convert to fraction form
   8,721.30/13,081.89 = 2,878.38/x
3. Step 3: Cross multiply
   8,721.30x = 13,081.89 × 2,878.38
4. Step 4: Simplify right side
   8,721.30x = 37,654,650.54
5. Step 5: Solve for x
   x = 37,654,650.54/8,721.30
6. Step 6: Final answer
   x = 4,317.55