Finding the Fourth Proportional to 78,720.04, 108,636.69 and 42,912.10

Step by Step Solution

1. Step 1: Write the proportion equation
   78,720.04 : 108,636.69 = 42,912.10 : x
2. Step 2: Convert to fraction form
   78,720.04/108,636.69 = 42,912.10/x
3. Step 3: Cross multiply
   78,720.04x = 108,636.69 × 42,912.10
4. Step 4: Simplify right side
   78,720.04x = 4,661,828,504.95
5. Step 5: Solve for x
   x = 4,661,828,504.95/78,720.04
6. Step 6: Final answer
   x = 59,220.35