Finding the Fourth Proportional to 1,429.65, 1,972.35 and 869.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,429.65 : 1,972.35 = 869.81 : x
2. Step 2: Convert to fraction form
   1,429.65/1,972.35 = 869.81/x
3. Step 3: Cross multiply
   1,429.65x = 1,972.35 × 869.81
4. Step 4: Simplify right side
   1,429.65x = 1,715,559.89
5. Step 5: Solve for x
   x = 1,715,559.89/1,429.65
6. Step 6: Final answer
   x = 1,199.99