Finding the Fourth Proportional to 1,557.77, 2,149.56 and 859.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,557.77 : 2,149.56 = 859.15 : x
2. Step 2: Convert to fraction form
   1,557.77/2,149.56 = 859.15/x
3. Step 3: Cross multiply
   1,557.77x = 2,149.56 × 859.15
4. Step 4: Simplify right side
   1,557.77x = 1,846,789.10
5. Step 5: Solve for x
   x = 1,846,789.10/1,557.77
6. Step 6: Final answer
   x = 1,185.53