Finding the Fourth Proportional to 13,978.13, 20,987.96 and 5,674.42

Step by Step Solution

1. Step 1: Write the proportion equation
   13,978.13 : 20,987.96 = 5,674.42 : x
2. Step 2: Convert to fraction form
   13,978.13/20,987.96 = 5,674.42/x
3. Step 3: Cross multiply
   13,978.13x = 20,987.96 × 5,674.42
4. Step 4: Simplify right side
   13,978.13x = 119,094,499.98
5. Step 5: Solve for x
   x = 119,094,499.98/13,978.13
6. Step 6: Final answer
   x = 8,520.06