Finding the Fourth Proportional to 1,429.11, 1,972.22 and 869.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,429.11 : 1,972.22 = 869.76 : x
2. Step 2: Convert to fraction form
   1,429.11/1,972.22 = 869.76/x
3. Step 3: Cross multiply
   1,429.11x = 1,972.22 × 869.76
4. Step 4: Simplify right side
   1,429.11x = 1,715,353.72
5. Step 5: Solve for x
   x = 1,715,353.72/1,429.11
6. Step 6: Final answer
   x = 1,200.30