Finding the Fourth Proportional to 1,389.52, 1,917.60 and 768.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.52 : 1,917.60 = 768.48 : x
2. Step 2: Convert to fraction form
   1,389.52/1,917.60 = 768.48/x
3. Step 3: Cross multiply
   1,389.52x = 1,917.60 × 768.48
4. Step 4: Simplify right side
   1,389.52x = 1,473,637.25
5. Step 5: Solve for x
   x = 1,473,637.25/1,389.52
6. Step 6: Final answer
   x = 1,060.54