Finding the Fourth Proportional to 1,429.36, 1,972.61 and 839.99

Step by Step Solution

1. Step 1: Write the proportion equation
   1,429.36 : 1,972.61 = 839.99 : x
2. Step 2: Convert to fraction form
   1,429.36/1,972.61 = 839.99/x
3. Step 3: Cross multiply
   1,429.36x = 1,972.61 × 839.99
4. Step 4: Simplify right side
   1,429.36x = 1,656,972.67
5. Step 5: Solve for x
   x = 1,656,972.67/1,429.36
6. Step 6: Final answer
   x = 1,159.24