Finding the Fourth Proportional to 3,612.72, 5,421.35 and 1,421.40

Step by Step Solution

1. Step 1: Write the proportion equation
   3,612.72 : 5,421.35 = 1,421.40 : x
2. Step 2: Convert to fraction form
   3,612.72/5,421.35 = 1,421.40/x
3. Step 3: Cross multiply
   3,612.72x = 5,421.35 × 1,421.40
4. Step 4: Simplify right side
   3,612.72x = 7,705,906.89
5. Step 5: Solve for x
   x = 7,705,906.89/3,612.72
6. Step 6: Final answer
   x = 2,132.99