Finding the Fourth Proportional to 7,086.93, 9,779.90 and 3,900.12

Step by Step Solution

1. Step 1: Write the proportion equation
   7,086.93 : 9,779.90 = 3,900.12 : x
2. Step 2: Convert to fraction form
   7,086.93/9,779.90 = 3,900.12/x
3. Step 3: Cross multiply
   7,086.93x = 9,779.90 × 3,900.12
4. Step 4: Simplify right side
   7,086.93x = 38,142,764.09
5. Step 5: Solve for x
   x = 38,142,764.09/7,086.93
6. Step 6: Final answer
   x = 5,382.13