Finding the Fourth Proportional to 1,429.70, 1,972.47 and 869.99

Step by Step Solution

1. Step 1: Write the proportion equation
   1,429.70 : 1,972.47 = 869.99 : x
2. Step 2: Convert to fraction form
   1,429.70/1,972.47 = 869.99/x
3. Step 3: Cross multiply
   1,429.70x = 1,972.47 × 869.99
4. Step 4: Simplify right side
   1,429.70x = 1,716,029.18
5. Step 5: Solve for x
   x = 1,716,029.18/1,429.70
6. Step 6: Final answer
   x = 1,200.27