Finding the Fourth Proportional to 1,399.35, 1,931.12 and 769.91

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.35 : 1,931.12 = 769.91 : x
2. Step 2: Convert to fraction form
   1,399.35/1,931.12 = 769.91/x
3. Step 3: Cross multiply
   1,399.35x = 1,931.12 × 769.91
4. Step 4: Simplify right side
   1,399.35x = 1,486,775.09
5. Step 5: Solve for x
   x = 1,486,775.09/1,399.35
6. Step 6: Final answer
   x = 1,062.48