Finding the Fourth Proportional to 1,420.66, 1,960.23 and 861.41

Step by Step Solution

1. Step 1: Write the proportion equation
   1,420.66 : 1,960.23 = 861.41 : x
2. Step 2: Convert to fraction form
   1,420.66/1,960.23 = 861.41/x
3. Step 3: Cross multiply
   1,420.66x = 1,960.23 × 861.41
4. Step 4: Simplify right side
   1,420.66x = 1,688,561.72
5. Step 5: Solve for x
   x = 1,688,561.72/1,420.66
6. Step 6: Final answer
   x = 1,188.58