Finding the Fourth Proportional to 7,086.89, 9,779.71 and 4,102.78

Step by Step Solution

1. Step 1: Write the proportion equation
   7,086.89 : 9,779.71 = 4,102.78 : x
2. Step 2: Convert to fraction form
   7,086.89/9,779.71 = 4,102.78/x
3. Step 3: Cross multiply
   7,086.89x = 9,779.71 × 4,102.78
4. Step 4: Simplify right side
   7,086.89x = 40,123,973.95
5. Step 5: Solve for x
   x = 40,123,973.95/7,086.89
6. Step 6: Final answer
   x = 5,661.72