Finding the Fourth Proportional to 1,620.56, 2,236.39 and 921.94

Step by Step Solution

1. Step 1: Write the proportion equation
   1,620.56 : 2,236.39 = 921.94 : x
2. Step 2: Convert to fraction form
   1,620.56/2,236.39 = 921.94/x
3. Step 3: Cross multiply
   1,620.56x = 2,236.39 × 921.94
4. Step 4: Simplify right side
   1,620.56x = 2,061,809.50
5. Step 5: Solve for x
   x = 2,061,809.50/1,620.56
6. Step 6: Final answer
   x = 1,272.28