Finding the Fourth Proportional to 13,978.08, 20,975.49 and 5,219.15

Step by Step Solution

1. Step 1: Write the proportion equation
   13,978.08 : 20,975.49 = 5,219.15 : x
2. Step 2: Convert to fraction form
   13,978.08/20,975.49 = 5,219.15/x
3. Step 3: Cross multiply
   13,978.08x = 20,975.49 × 5,219.15
4. Step 4: Simplify right side
   13,978.08x = 109,474,123.76
5. Step 5: Solve for x
   x = 109,474,123.76/13,978.08
6. Step 6: Final answer
   x = 7,831.84