Finding the Fourth Proportional to 1,431.23, 1,974.78 and 871.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,431.23 : 1,974.78 = 871.61 : x
2. Step 2: Convert to fraction form
   1,431.23/1,974.78 = 871.61/x
3. Step 3: Cross multiply
   1,431.23x = 1,974.78 × 871.61
4. Step 4: Simplify right side
   1,431.23x = 1,721,228.12
5. Step 5: Solve for x
   x = 1,721,228.12/1,431.23
6. Step 6: Final answer
   x = 1,202.63