Finding the Fourth Proportional to 1,638.91, 2,261.69 and 892.87

Step by Step Solution

1. Step 1: Write the proportion equation
   1,638.91 : 2,261.69 = 892.87 : x
2. Step 2: Convert to fraction form
   1,638.91/2,261.69 = 892.87/x
3. Step 3: Cross multiply
   1,638.91x = 2,261.69 × 892.87
4. Step 4: Simplify right side
   1,638.91x = 2,019,385.03
5. Step 5: Solve for x
   x = 2,019,385.03/1,638.91
6. Step 6: Final answer
   x = 1,232.15