Finding the Fourth Proportional to 10,978.80, 16,464.15 and 5,430.30

Step by Step Solution

1. Step 1: Write the proportion equation
   10,978.80 : 16,464.15 = 5,430.30 : x
2. Step 2: Convert to fraction form
   10,978.80/16,464.15 = 5,430.30/x
3. Step 3: Cross multiply
   10,978.80x = 16,464.15 × 5,430.30
4. Step 4: Simplify right side
   10,978.80x = 89,405,273.75
5. Step 5: Solve for x
   x = 89,405,273.75/10,978.80
6. Step 6: Final answer
   x = 8,143.45