Finding the Fourth Proportional to 1,429.28, 1,971.96 and 839.84

Step by Step Solution

1. Step 1: Write the proportion equation
   1,429.28 : 1,971.96 = 839.84 : x
2. Step 2: Convert to fraction form
   1,429.28/1,971.96 = 839.84/x
3. Step 3: Cross multiply
   1,429.28x = 1,971.96 × 839.84
4. Step 4: Simplify right side
   1,429.28x = 1,656,130.89
5. Step 5: Solve for x
   x = 1,656,130.89/1,429.28
6. Step 6: Final answer
   x = 1,158.72