Finding the Fourth Proportional to 1,853.90, 2,780.72 and 1,123.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,853.90 : 2,780.72 = 1,123.28 : x
2. Step 2: Convert to fraction form
   1,853.90/2,780.72 = 1,123.28/x
3. Step 3: Cross multiply
   1,853.90x = 2,780.72 × 1,123.28
4. Step 4: Simplify right side
   1,853.90x = 3,123,527.16
5. Step 5: Solve for x
   x = 3,123,527.16/1,853.90
6. Step 6: Final answer
   x = 1,684.84