Finding the Fourth Proportional to 2,820.32, 3,892.20 and 1,561.63

Step by Step Solution

1. Step 1: Write the proportion equation
   2,820.32 : 3,892.20 = 1,561.63 : x
2. Step 2: Convert to fraction form
   2,820.32/3,892.20 = 1,561.63/x
3. Step 3: Cross multiply
   2,820.32x = 3,892.20 × 1,561.63
4. Step 4: Simplify right side
   2,820.32x = 6,078,176.78
5. Step 5: Solve for x
   x = 6,078,176.78/2,820.32
6. Step 6: Final answer
   x = 2,155.14