Finding the Fourth Proportional to 1,355.56, 1,870.68 and 766.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,355.56 : 1,870.68 = 766.15 : x
2. Step 2: Convert to fraction form
   1,355.56/1,870.68 = 766.15/x
3. Step 3: Cross multiply
   1,355.56x = 1,870.68 × 766.15
4. Step 4: Simplify right side
   1,355.56x = 1,433,221.48
5. Step 5: Solve for x
   x = 1,433,221.48/1,355.56
6. Step 6: Final answer
   x = 1,057.29