Finding the Fourth Proportional to 2,820.45, 3,892.17 and 1,561.47

Step by Step Solution

1. Step 1: Write the proportion equation
   2,820.45 : 3,892.17 = 1,561.47 : x
2. Step 2: Convert to fraction form
   2,820.45/3,892.17 = 1,561.47/x
3. Step 3: Cross multiply
   2,820.45x = 3,892.17 × 1,561.47
4. Step 4: Simplify right side
   2,820.45x = 6,077,506.69
5. Step 5: Solve for x
   x = 6,077,506.69/2,820.45
6. Step 6: Final answer
   x = 2,154.80