Finding the Fourth Proportional to 1,387.88, 1,914.42 and 827.99

Step by Step Solution

1. Step 1: Write the proportion equation
   1,387.88 : 1,914.42 = 827.99 : x
2. Step 2: Convert to fraction form
   1,387.88/1,914.42 = 827.99/x
3. Step 3: Cross multiply
   1,387.88x = 1,914.42 × 827.99
4. Step 4: Simplify right side
   1,387.88x = 1,585,120.62
5. Step 5: Solve for x
   x = 1,585,120.62/1,387.88
6. Step 6: Final answer
   x = 1,142.12