Finding the Fourth Proportional to 3,688.22, 5,528.32 and 1,815.40

Step by Step Solution

1. Step 1: Write the proportion equation
   3,688.22 : 5,528.32 = 1,815.40 : x
2. Step 2: Convert to fraction form
   3,688.22/5,528.32 = 1,815.40/x
3. Step 3: Cross multiply
   3,688.22x = 5,528.32 × 1,815.40
4. Step 4: Simplify right side
   3,688.22x = 10,036,093.61
5. Step 5: Solve for x
   x = 10,036,093.61/3,688.22
6. Step 6: Final answer
   x = 2,721.12