Finding the Fourth Proportional to 1,386.52, 2,078.30 and 691.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,386.52 : 2,078.30 = 691.82 : x
2. Step 2: Convert to fraction form
   1,386.52/2,078.30 = 691.82/x
3. Step 3: Cross multiply
   1,386.52x = 2,078.30 × 691.82
4. Step 4: Simplify right side
   1,386.52x = 1,437,809.51
5. Step 5: Solve for x
   x = 1,437,809.51/1,386.52
6. Step 6: Final answer
   x = 1,036.99