Finding the Fourth Proportional to 1,553.31, 2,143.53 and 890.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,553.31 : 2,143.53 = 890.28 : x
2. Step 2: Convert to fraction form
   1,553.31/2,143.53 = 890.28/x
3. Step 3: Cross multiply
   1,553.31x = 2,143.53 × 890.28
4. Step 4: Simplify right side
   1,553.31x = 1,908,341.89
5. Step 5: Solve for x
   x = 1,908,341.89/1,553.31
6. Step 6: Final answer
   x = 1,228.56