Finding the Fourth Proportional to 76,781.32, 105,978.02 and 49,990.76

Step by Step Solution

1. Step 1: Write the proportion equation
   76,781.32 : 105,978.02 = 49,990.76 : x
2. Step 2: Convert to fraction form
   76,781.32/105,978.02 = 49,990.76/x
3. Step 3: Cross multiply
   76,781.32x = 105,978.02 × 49,990.76
4. Step 4: Simplify right side
   76,781.32x = 5,297,921,763.10
5. Step 5: Solve for x
   x = 5,297,921,763.10/76,781.32
6. Step 6: Final answer
   x = 69,000.14