Finding the Fourth Proportional to 1,355.12, 1,870.14 and 765.68

Step by Step Solution

1. Step 1: Write the proportion equation
   1,355.12 : 1,870.14 = 765.68 : x
2. Step 2: Convert to fraction form
   1,355.12/1,870.14 = 765.68/x
3. Step 3: Cross multiply
   1,355.12x = 1,870.14 × 765.68
4. Step 4: Simplify right side
   1,355.12x = 1,431,928.80
5. Step 5: Solve for x
   x = 1,431,928.80/1,355.12
6. Step 6: Final answer
   x = 1,056.68