Finding the Fourth Proportional to 1,906.32, 2,857.51 and 931.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,906.32 : 2,857.51 = 931.21 : x
2. Step 2: Convert to fraction form
   1,906.32/2,857.51 = 931.21/x
3. Step 3: Cross multiply
   1,906.32x = 2,857.51 × 931.21
4. Step 4: Simplify right side
   1,906.32x = 2,660,941.89
5. Step 5: Solve for x
   x = 2,660,941.89/1,906.32
6. Step 6: Final answer
   x = 1,395.85