Finding the Fourth Proportional to 1,345.91, 1,857.17 and 778.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,345.91 : 1,857.17 = 778.83 : x
2. Step 2: Convert to fraction form
   1,345.91/1,857.17 = 778.83/x
3. Step 3: Cross multiply
   1,345.91x = 1,857.17 × 778.83
4. Step 4: Simplify right side
   1,345.91x = 1,446,415.82
5. Step 5: Solve for x
   x = 1,446,415.82/1,345.91
6. Step 6: Final answer
   x = 1,074.68