Finding the Fourth Proportional to 2,820.78, 3,893.31 and 1,642.02

Step by Step Solution

1. Step 1: Write the proportion equation
   2,820.78 : 3,893.31 = 1,642.02 : x
2. Step 2: Convert to fraction form
   2,820.78/3,893.31 = 1,642.02/x
3. Step 3: Cross multiply
   2,820.78x = 3,893.31 × 1,642.02
4. Step 4: Simplify right side
   2,820.78x = 6,392,892.89
5. Step 5: Solve for x
   x = 6,392,892.89/2,820.78
6. Step 6: Final answer
   x = 2,266.36