Finding the Fourth Proportional to 1,421.03, 1,961.16 and 861.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,421.03 : 1,961.16 = 861.89 : x
2. Step 2: Convert to fraction form
   1,421.03/1,961.16 = 861.89/x
3. Step 3: Cross multiply
   1,421.03x = 1,961.16 × 861.89
4. Step 4: Simplify right side
   1,421.03x = 1,690,307.03
5. Step 5: Solve for x
   x = 1,690,307.03/1,421.03
6. Step 6: Final answer
   x = 1,189.50