Finding the Fourth Proportional to 1,354.86, 1,869.96 and 765.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,354.86 : 1,869.96 = 765.60 : x
2. Step 2: Convert to fraction form
   1,354.86/1,869.96 = 765.60/x
3. Step 3: Cross multiply
   1,354.86x = 1,869.96 × 765.60
4. Step 4: Simplify right side
   1,354.86x = 1,431,641.38
5. Step 5: Solve for x
   x = 1,431,641.38/1,354.86
6. Step 6: Final answer
   x = 1,056.67