Finding the Fourth Proportional to 5,420.72, 8,131.39 and 5,181.17

Step by Step Solution

1. Step 1: Write the proportion equation
   5,420.72 : 8,131.39 = 5,181.17 : x
2. Step 2: Convert to fraction form
   5,420.72/8,131.39 = 5,181.17/x
3. Step 3: Cross multiply
   5,420.72x = 8,131.39 × 5,181.17
4. Step 4: Simplify right side
   5,420.72x = 42,130,060.32
5. Step 5: Solve for x
   x = 42,130,060.32/5,420.72
6. Step 6: Final answer
   x = 7,772.04