Finding the Fourth Proportional to 1,392.27, 1,921.34 and 762.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,392.27 : 1,921.34 = 762.80 : x
2. Step 2: Convert to fraction form
   1,392.27/1,921.34 = 762.80/x
3. Step 3: Cross multiply
   1,392.27x = 1,921.34 × 762.80
4. Step 4: Simplify right side
   1,392.27x = 1,465,594.34
5. Step 5: Solve for x
   x = 1,465,594.34/1,392.27
6. Step 6: Final answer
   x = 1,052.67