Finding the Fourth Proportional to 1,860.31, 2,790.96 and 820.53

Step by Step Solution

1. Step 1: Write the proportion equation
   1,860.31 : 2,790.96 = 820.53 : x
2. Step 2: Convert to fraction form
   1,860.31/2,790.96 = 820.53/x
3. Step 3: Cross multiply
   1,860.31x = 2,790.96 × 820.53
4. Step 4: Simplify right side
   1,860.31x = 2,290,048.35
5. Step 5: Solve for x
   x = 2,290,048.35/1,860.31
6. Step 6: Final answer
   x = 1,231.00