Finding the Fourth Proportional to 5,421.20, 8,131.67 and 2,499.50

Step by Step Solution

1. Step 1: Write the proportion equation
   5,421.20 : 8,131.67 = 2,499.50 : x
2. Step 2: Convert to fraction form
   5,421.20/8,131.67 = 2,499.50/x
3. Step 3: Cross multiply
   5,421.20x = 8,131.67 × 2,499.50
4. Step 4: Simplify right side
   5,421.20x = 20,325,109.17
5. Step 5: Solve for x
   x = 20,325,109.17/5,421.20
6. Step 6: Final answer
   x = 3,749.19