Finding the Fourth Proportional to 78,131.68, 107,821.67 and 42,321.61

Step by Step Solution

1. Step 1: Write the proportion equation
   78,131.68 : 107,821.67 = 42,321.61 : x
2. Step 2: Convert to fraction form
   78,131.68/107,821.67 = 42,321.61/x
3. Step 3: Cross multiply
   78,131.68x = 107,821.67 × 42,321.61
4. Step 4: Simplify right side
   78,131.68x = 4,563,186,667.29
5. Step 5: Solve for x
   x = 4,563,186,667.29/78,131.68
6. Step 6: Final answer
   x = 58,403.80