Finding the Fourth Proportional to 1,620.91, 2,236.59 and 922.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,620.91 : 2,236.59 = 922.15 : x
2. Step 2: Convert to fraction form
   1,620.91/2,236.59 = 922.15/x
3. Step 3: Cross multiply
   1,620.91x = 2,236.59 × 922.15
4. Step 4: Simplify right side
   1,620.91x = 2,062,471.47
5. Step 5: Solve for x
   x = 2,062,471.47/1,620.91
6. Step 6: Final answer
   x = 1,272.42