Finding the Fourth Proportional to 1,287.78, 1,774.55 and 932.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,287.78 : 1,774.55 = 932.57 : x
2. Step 2: Convert to fraction form
   1,287.78/1,774.55 = 932.57/x
3. Step 3: Cross multiply
   1,287.78x = 1,774.55 × 932.57
4. Step 4: Simplify right side
   1,287.78x = 1,654,878.56
5. Step 5: Solve for x
   x = 1,654,878.56/1,287.78
6. Step 6: Final answer
   x = 1,285.06