Finding the Fourth Proportional to 1,355.72, 1,870.80 and 766.14

Step by Step Solution

1. Step 1: Write the proportion equation
   1,355.72 : 1,870.80 = 766.14 : x
2. Step 2: Convert to fraction form
   1,355.72/1,870.80 = 766.14/x
3. Step 3: Cross multiply
   1,355.72x = 1,870.80 × 766.14
4. Step 4: Simplify right side
   1,355.72x = 1,433,294.71
5. Step 5: Solve for x
   x = 1,433,294.71/1,355.72
6. Step 6: Final answer
   x = 1,057.22