Finding the Fourth Proportional to 2,119.32, 3,178.89 and 820.71

Step by Step Solution

1. Step 1: Write the proportion equation
   2,119.32 : 3,178.89 = 820.71 : x
2. Step 2: Convert to fraction form
   2,119.32/3,178.89 = 820.71/x
3. Step 3: Cross multiply
   2,119.32x = 3,178.89 × 820.71
4. Step 4: Simplify right side
   2,119.32x = 2,608,946.81
5. Step 5: Solve for x
   x = 2,608,946.81/2,119.32
6. Step 6: Final answer
   x = 1,231.03