Finding the Fourth Proportional to 13,319.10, 19,981.49 and 3,959.15

Step by Step Solution

1. Step 1: Write the proportion equation
   13,319.10 : 19,981.49 = 3,959.15 : x
2. Step 2: Convert to fraction form
   13,319.10/19,981.49 = 3,959.15/x
3. Step 3: Cross multiply
   13,319.10x = 19,981.49 × 3,959.15
4. Step 4: Simplify right side
   13,319.10x = 79,109,596.43
5. Step 5: Solve for x
   x = 79,109,596.43/13,319.10
6. Step 6: Final answer
   x = 5,939.56