Finding the Fourth Proportional to 1,356.16, 1,872.16 and 890.24

Step by Step Solution

1. Step 1: Write the proportion equation
   1,356.16 : 1,872.16 = 890.24 : x
2. Step 2: Convert to fraction form
   1,356.16/1,872.16 = 890.24/x
3. Step 3: Cross multiply
   1,356.16x = 1,872.16 × 890.24
4. Step 4: Simplify right side
   1,356.16x = 1,666,671.72
5. Step 5: Solve for x
   x = 1,666,671.72/1,356.16
6. Step 6: Final answer
   x = 1,228.96