Finding the Fourth Proportional to 76,671.78, 105,810.17 and 42,678.12

Step by Step Solution

1. Step 1: Write the proportion equation
   76,671.78 : 105,810.17 = 42,678.12 : x
2. Step 2: Convert to fraction form
   76,671.78/105,810.17 = 42,678.12/x
3. Step 3: Cross multiply
   76,671.78x = 105,810.17 × 42,678.12
4. Step 4: Simplify right side
   76,671.78x = 4,515,778,919.09
5. Step 5: Solve for x
   x = 4,515,778,919.09/76,671.78
6. Step 6: Final answer
   x = 58,897.54