Finding the Fourth Proportional to 1,429.72, 1,972.36 and 839.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,429.72 : 1,972.36 = 839.98 : x
2. Step 2: Convert to fraction form
   1,429.72/1,972.36 = 839.98/x
3. Step 3: Cross multiply
   1,429.72x = 1,972.36 × 839.98
4. Step 4: Simplify right side
   1,429.72x = 1,656,742.95
5. Step 5: Solve for x
   x = 1,656,742.95/1,429.72
6. Step 6: Final answer
   x = 1,158.79