Finding the Fourth Proportional to 1,857.72, 2,780.82 and 1,089.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,857.72 : 2,780.82 = 1,089.72 : x
2. Step 2: Convert to fraction form
   1,857.72/2,780.82 = 1,089.72/x
3. Step 3: Cross multiply
   1,857.72x = 2,780.82 × 1,089.72
4. Step 4: Simplify right side
   1,857.72x = 3,030,315.17
5. Step 5: Solve for x
   x = 3,030,315.17/1,857.72
6. Step 6: Final answer
   x = 1,631.20