Finding the Fourth Proportional to 1,389.50, 1,917.52 and 768.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.50 : 1,917.52 = 768.50 : x
2. Step 2: Convert to fraction form
   1,389.50/1,917.52 = 768.50/x
3. Step 3: Cross multiply
   1,389.50x = 1,917.52 × 768.50
4. Step 4: Simplify right side
   1,389.50x = 1,473,614.12
5. Step 5: Solve for x
   x = 1,473,614.12/1,389.50
6. Step 6: Final answer
   x = 1,060.54