Finding the Fourth Proportional to 1,820.81, 2,732.37 and 780.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,820.81 : 2,732.37 = 780.82 : x
2. Step 2: Convert to fraction form
   1,820.81/2,732.37 = 780.82/x
3. Step 3: Cross multiply
   1,820.81x = 2,732.37 × 780.82
4. Step 4: Simplify right side
   1,820.81x = 2,133,471.58
5. Step 5: Solve for x
   x = 2,133,471.58/1,820.81
6. Step 6: Final answer
   x = 1,171.72