Finding the Fourth Proportional to 78,128.02, 107,816.47 and 42,318.12

Step by Step Solution

1. Step 1: Write the proportion equation
   78,128.02 : 107,816.47 = 42,318.12 : x
2. Step 2: Convert to fraction form
   78,128.02/107,816.47 = 42,318.12/x
3. Step 3: Cross multiply
   78,128.02x = 107,816.47 × 42,318.12
4. Step 4: Simplify right side
   78,128.02x = 4,562,590,315.44
5. Step 5: Solve for x
   x = 4,562,590,315.44/78,128.02
6. Step 6: Final answer
   x = 58,398.90