Finding the Fourth Proportional to 1,429.29, 1,971.90 and 869.36

Step by Step Solution

1. Step 1: Write the proportion equation
   1,429.29 : 1,971.90 = 869.36 : x
2. Step 2: Convert to fraction form
   1,429.29/1,971.90 = 869.36/x
3. Step 3: Cross multiply
   1,429.29x = 1,971.90 × 869.36
4. Step 4: Simplify right side
   1,429.29x = 1,714,281.12
5. Step 5: Solve for x
   x = 1,714,281.12/1,429.29
6. Step 6: Final answer
   x = 1,199.39