Finding the Fourth Proportional to 30,978.76, 42,749.40 and 16,831.24

Step by Step Solution

1. Step 1: Write the proportion equation
   30,978.76 : 42,749.40 = 16,831.24 : x
2. Step 2: Convert to fraction form
   30,978.76/42,749.40 = 16,831.24/x
3. Step 3: Cross multiply
   30,978.76x = 42,749.40 × 16,831.24
4. Step 4: Simplify right side
   30,978.76x = 719,525,411.26
5. Step 5: Solve for x
   x = 719,525,411.26/30,978.76
6. Step 6: Final answer
   x = 23,226.41