Finding the Fourth Proportional to 7,085.90, 9,778.52 and 3,942.10

Step by Step Solution

1. Step 1: Write the proportion equation
   7,085.90 : 9,778.52 = 3,942.10 : x
2. Step 2: Convert to fraction form
   7,085.90/9,778.52 = 3,942.10/x
3. Step 3: Cross multiply
   7,085.90x = 9,778.52 × 3,942.10
4. Step 4: Simplify right side
   7,085.90x = 38,547,903.69
5. Step 5: Solve for x
   x = 38,547,903.69/7,085.90
6. Step 6: Final answer
   x = 5,440.09