Finding the Fourth Proportional to 1,398.33, 1,929.61 and 768.87

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.33 : 1,929.61 = 768.87 : x
2. Step 2: Convert to fraction form
   1,398.33/1,929.61 = 768.87/x
3. Step 3: Cross multiply
   1,398.33x = 1,929.61 × 768.87
4. Step 4: Simplify right side
   1,398.33x = 1,483,619.24
5. Step 5: Solve for x
   x = 1,483,619.24/1,398.33
6. Step 6: Final answer
   x = 1,060.99