Finding the Fourth Proportional to 1,638.58, 2,261.25 and 892.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,638.58 : 2,261.25 = 892.56 : x
2. Step 2: Convert to fraction form
   1,638.58/2,261.25 = 892.56/x
3. Step 3: Cross multiply
   1,638.58x = 2,261.25 × 892.56
4. Step 4: Simplify right side
   1,638.58x = 2,018,301.30
5. Step 5: Solve for x
   x = 2,018,301.30/1,638.58
6. Step 6: Final answer
   x = 1,231.74