Finding the Fourth Proportional to 13,321.08, 19,978.20 and 3,958.89

Step by Step Solution

1. Step 1: Write the proportion equation
   13,321.08 : 19,978.20 = 3,958.89 : x
2. Step 2: Convert to fraction form
   13,321.08/19,978.20 = 3,958.89/x
3. Step 3: Cross multiply
   13,321.08x = 19,978.20 × 3,958.89
4. Step 4: Simplify right side
   13,321.08x = 79,091,496.20
5. Step 5: Solve for x
   x = 79,091,496.20/13,321.08
6. Step 6: Final answer
   x = 5,937.32