Finding the Fourth Proportional to 1,860.59, 2,791.31 and 820.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,860.59 : 2,791.31 = 820.89 : x
2. Step 2: Convert to fraction form
   1,860.59/2,791.31 = 820.89/x
3. Step 3: Cross multiply
   1,860.59x = 2,791.31 × 820.89
4. Step 4: Simplify right side
   1,860.59x = 2,291,344.51
5. Step 5: Solve for x
   x = 2,291,344.51/1,860.59
6. Step 6: Final answer
   x = 1,231.52