Finding the Fourth Proportional to 105,428.76, 145,477.32 and 62,978.28

Step by Step Solution

1. Step 1: Write the proportion equation
   105,428.76 : 145,477.32 = 62,978.28 : x
2. Step 2: Convert to fraction form
   105,428.76/145,477.32 = 62,978.28/x
3. Step 3: Cross multiply
   105,428.76x = 145,477.32 × 62,978.28
4. Step 4: Simplify right side
   105,428.76x = 9,161,911,392.61
5. Step 5: Solve for x
   x = 9,161,911,392.61/105,428.76
6. Step 6: Final answer
   x = 86,901.44