Finding the Fourth Proportional to 2,591.03, 3,886.52 and 643.22

Step by Step Solution

1. Step 1: Write the proportion equation
   2,591.03 : 3,886.52 = 643.22 : x
2. Step 2: Convert to fraction form
   2,591.03/3,886.52 = 643.22/x
3. Step 3: Cross multiply
   2,591.03x = 3,886.52 × 643.22
4. Step 4: Simplify right side
   2,591.03x = 2,499,879.32
5. Step 5: Solve for x
   x = 2,499,879.32/2,591.03
6. Step 6: Final answer
   x = 964.82