Finding the Fourth Proportional to 1,421.32, 1,960.82 and 861.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,421.32 : 1,960.82 = 861.88 : x
2. Step 2: Convert to fraction form
   1,421.32/1,960.82 = 861.88/x
3. Step 3: Cross multiply
   1,421.32x = 1,960.82 × 861.88
4. Step 4: Simplify right side
   1,421.32x = 1,689,991.54
5. Step 5: Solve for x
   x = 1,689,991.54/1,421.32
6. Step 6: Final answer
   x = 1,189.03