Finding the Fourth Proportional to 13,319.76, 19,980.42 and 3,458.79

Step by Step Solution

1. Step 1: Write the proportion equation
   13,319.76 : 19,980.42 = 3,458.79 : x
2. Step 2: Convert to fraction form
   13,319.76/19,980.42 = 3,458.79/x
3. Step 3: Cross multiply
   13,319.76x = 19,980.42 × 3,458.79
4. Step 4: Simplify right side
   13,319.76x = 69,108,076.89
5. Step 5: Solve for x
   x = 69,108,076.89/13,319.76
6. Step 6: Final answer
   x = 5,188.39