Finding the Fourth Proportional to 1,392.14, 1,919.96 and 920.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,392.14 : 1,919.96 = 920.05 : x
2. Step 2: Convert to fraction form
   1,392.14/1,919.96 = 920.05/x
3. Step 3: Cross multiply
   1,392.14x = 1,919.96 × 920.05
4. Step 4: Simplify right side
   1,392.14x = 1,766,459.20
5. Step 5: Solve for x
   x = 1,766,459.20/1,392.14
6. Step 6: Final answer
   x = 1,268.88