Finding the Fourth Proportional to 2,172.06, 3,256.70 and 921.98

Step by Step Solution

1. Step 1: Write the proportion equation
   2,172.06 : 3,256.70 = 921.98 : x
2. Step 2: Convert to fraction form
   2,172.06/3,256.70 = 921.98/x
3. Step 3: Cross multiply
   2,172.06x = 3,256.70 × 921.98
4. Step 4: Simplify right side
   2,172.06x = 3,002,612.27
5. Step 5: Solve for x
   x = 3,002,612.27/2,172.06
6. Step 6: Final answer
   x = 1,382.38