Finding the Fourth Proportional to 1,443.86, 2,164.57 and 621.51

Step by Step Solution

1. Step 1: Write the proportion equation
   1,443.86 : 2,164.57 = 621.51 : x
2. Step 2: Convert to fraction form
   1,443.86/2,164.57 = 621.51/x
3. Step 3: Cross multiply
   1,443.86x = 2,164.57 × 621.51
4. Step 4: Simplify right side
   1,443.86x = 1,345,295.73
5. Step 5: Solve for x
   x = 1,345,295.73/1,443.86
6. Step 6: Final answer
   x = 931.74