Finding the Fourth Proportional to 2,090.98, 3,136.02 and 857.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,090.98 : 3,136.02 = 857.20 : x
2. Step 2: Convert to fraction form
   2,090.98/3,136.02 = 857.20/x
3. Step 3: Cross multiply
   2,090.98x = 3,136.02 × 857.20
4. Step 4: Simplify right side
   2,090.98x = 2,688,196.34
5. Step 5: Solve for x
   x = 2,688,196.34/2,090.98
6. Step 6: Final answer
   x = 1,285.62