Finding the Fourth Proportional to 78,200.20, 107,916.42 and 42,390.10

Step by Step Solution

1. Step 1: Write the proportion equation
   78,200.20 : 107,916.42 = 42,390.10 : x
2. Step 2: Convert to fraction form
   78,200.20/107,916.42 = 42,390.10/x
3. Step 3: Cross multiply
   78,200.20x = 107,916.42 × 42,390.10
4. Step 4: Simplify right side
   78,200.20x = 4,574,587,835.44
5. Step 5: Solve for x
   x = 4,574,587,835.44/78,200.20
6. Step 6: Final answer
   x = 58,498.42