Finding the Fourth Proportional to 1,389.34, 1,917.12 and 768.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.34 : 1,917.12 = 768.34 : x
2. Step 2: Convert to fraction form
   1,389.34/1,917.12 = 768.34/x
3. Step 3: Cross multiply
   1,389.34x = 1,917.12 × 768.34
4. Step 4: Simplify right side
   1,389.34x = 1,472,999.98
5. Step 5: Solve for x
   x = 1,472,999.98/1,389.34
6. Step 6: Final answer
   x = 1,060.22