Finding the Fourth Proportional to 13,758.61, 20,638.79 and 3,898.62

Step by Step Solution

1. Step 1: Write the proportion equation
   13,758.61 : 20,638.79 = 3,898.62 : x
2. Step 2: Convert to fraction form
   13,758.61/20,638.79 = 3,898.62/x
3. Step 3: Cross multiply
   13,758.61x = 20,638.79 × 3,898.62
4. Step 4: Simplify right side
   13,758.61x = 80,462,799.47
5. Step 5: Solve for x
   x = 80,462,799.47/13,758.61
6. Step 6: Final answer
   x = 5,848.18