Finding the Fourth Proportional to 13,731.31, 20,598.18 and 3,870.69

Step by Step Solution

1. Step 1: Write the proportion equation
   13,731.31 : 20,598.18 = 3,870.69 : x
2. Step 2: Convert to fraction form
   13,731.31/20,598.18 = 3,870.69/x
3. Step 3: Cross multiply
   13,731.31x = 20,598.18 × 3,870.69
4. Step 4: Simplify right side
   13,731.31x = 79,729,169.34
5. Step 5: Solve for x
   x = 79,729,169.34/13,731.31
6. Step 6: Final answer
   x = 5,806.38