Finding the Fourth Proportional to 21,060.42, 31,590.54 and 5,478

Step by Step Solution

1. Step 1: Write the proportion equation
   21,060.42 : 31,590.54 = 5,478 : x
2. Step 2: Convert to fraction form
   21,060.42/31,590.54 = 5,478/x
3. Step 3: Cross multiply
   21,060.42x = 31,590.54 × 5,478
4. Step 4: Simplify right side
   21,060.42x = 173,052,978.12
5. Step 5: Solve for x
   x = 173,052,978.12/21,060.42
6. Step 6: Final answer
   x = 8,216.98