Finding the Fourth Proportional to 7,085.86, 9,778.54 and 3,942.05

Step by Step Solution

1. Step 1: Write the proportion equation
   7,085.86 : 9,778.54 = 3,942.05 : x
2. Step 2: Convert to fraction form
   7,085.86/9,778.54 = 3,942.05/x
3. Step 3: Cross multiply
   7,085.86x = 9,778.54 × 3,942.05
4. Step 4: Simplify right side
   7,085.86x = 38,547,493.61
5. Step 5: Solve for x
   x = 38,547,493.61/7,085.86
6. Step 6: Final answer
   x = 5,440.06