Finding the Fourth Proportional to 1,392.25, 1,920.42 and 972.45

Step by Step Solution

1. Step 1: Write the proportion equation
   1,392.25 : 1,920.42 = 972.45 : x
2. Step 2: Convert to fraction form
   1,392.25/1,920.42 = 972.45/x
3. Step 3: Cross multiply
   1,392.25x = 1,920.42 × 972.45
4. Step 4: Simplify right side
   1,392.25x = 1,867,512.43
5. Step 5: Solve for x
   x = 1,867,512.43/1,392.25
6. Step 6: Final answer
   x = 1,341.36