Finding the Fourth Proportional to 1,377.20, 1,900.20 and 817.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,377.20 : 1,900.20 = 817.82 : x
2. Step 2: Convert to fraction form
   1,377.20/1,900.20 = 817.82/x
3. Step 3: Cross multiply
   1,377.20x = 1,900.20 × 817.82
4. Step 4: Simplify right side
   1,377.20x = 1,554,012.06
5. Step 5: Solve for x
   x = 1,554,012.06/1,377.20
6. Step 6: Final answer
   x = 1,128.39