Finding the Fourth Proportional to 1,392.72, 1,922.28 and 1,020.24

Step by Step Solution

1. Step 1: Write the proportion equation
   1,392.72 : 1,922.28 = 1,020.24 : x
2. Step 2: Convert to fraction form
   1,392.72/1,922.28 = 1,020.24/x
3. Step 3: Cross multiply
   1,392.72x = 1,922.28 × 1,020.24
4. Step 4: Simplify right side
   1,392.72x = 1,961,186.95
5. Step 5: Solve for x
   x = 1,961,186.95/1,392.72
6. Step 6: Final answer
   x = 1,408.17