Finding the Fourth Proportional to 3,938.31, 5,906.64 and 1,857.42

Step by Step Solution

1. Step 1: Write the proportion equation
   3,938.31 : 5,906.64 = 1,857.42 : x
2. Step 2: Convert to fraction form
   3,938.31/5,906.64 = 1,857.42/x
3. Step 3: Cross multiply
   3,938.31x = 5,906.64 × 1,857.42
4. Step 4: Simplify right side
   3,938.31x = 10,971,111.27
5. Step 5: Solve for x
   x = 10,971,111.27/3,938.31
6. Step 6: Final answer
   x = 2,785.74