Finding the Fourth Proportional to 1,019.61, 1,403.98 and 871.92

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.61 : 1,403.98 = 871.92 : x
2. Step 2: Convert to fraction form
   1,019.61/1,403.98 = 871.92/x
3. Step 3: Cross multiply
   1,019.61x = 1,403.98 × 871.92
4. Step 4: Simplify right side
   1,019.61x = 1,224,156.06
5. Step 5: Solve for x
   x = 1,224,156.06/1,019.61
6. Step 6: Final answer
   x = 1,200.61