Finding the Fourth Proportional to 1,429.25, 1,972.40 and 839.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,429.25 : 1,972.40 = 839.81 : x
2. Step 2: Convert to fraction form
   1,429.25/1,972.40 = 839.81/x
3. Step 3: Cross multiply
   1,429.25x = 1,972.40 × 839.81
4. Step 4: Simplify right side
   1,429.25x = 1,656,441.98
5. Step 5: Solve for x
   x = 1,656,441.98/1,429.25
6. Step 6: Final answer
   x = 1,158.96