Finding the Fourth Proportional to 1,355.13, 1,870.17 and 765.77

Step by Step Solution

1. Step 1: Write the proportion equation
   1,355.13 : 1,870.17 = 765.77 : x
2. Step 2: Convert to fraction form
   1,355.13/1,870.17 = 765.77/x
3. Step 3: Cross multiply
   1,355.13x = 1,870.17 × 765.77
4. Step 4: Simplify right side
   1,355.13x = 1,432,122.69
5. Step 5: Solve for x
   x = 1,432,122.69/1,355.13
6. Step 6: Final answer
   x = 1,056.82