Finding the Fourth Proportional to 1,916.50, 2,875.73 and 820.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,916.50 : 2,875.73 = 820.57 : x
2. Step 2: Convert to fraction form
   1,916.50/2,875.73 = 820.57/x
3. Step 3: Cross multiply
   1,916.50x = 2,875.73 × 820.57
4. Step 4: Simplify right side
   1,916.50x = 2,359,726.47
5. Step 5: Solve for x
   x = 2,359,726.47/1,916.50
6. Step 6: Final answer
   x = 1,231.27