Finding the Fourth Proportional to 76,789.80, 105,978.51 and 42,801.39

Step by Step Solution

1. Step 1: Write the proportion equation
   76,789.80 : 105,978.51 = 42,801.39 : x
2. Step 2: Convert to fraction form
   76,789.80/105,978.51 = 42,801.39/x
3. Step 3: Cross multiply
   76,789.80x = 105,978.51 × 42,801.39
4. Step 4: Simplify right side
   76,789.80x = 4,536,027,538.13
5. Step 5: Solve for x
   x = 4,536,027,538.13/76,789.80
6. Step 6: Final answer
   x = 59,070.70