Finding the Fourth Proportional to 2,670.03, 4,005.72 and 821.07

Step by Step Solution

1. Step 1: Write the proportion equation
   2,670.03 : 4,005.72 = 821.07 : x
2. Step 2: Convert to fraction form
   2,670.03/4,005.72 = 821.07/x
3. Step 3: Cross multiply
   2,670.03x = 4,005.72 × 821.07
4. Step 4: Simplify right side
   2,670.03x = 3,288,976.52
5. Step 5: Solve for x
   x = 3,288,976.52/2,670.03
6. Step 6: Final answer
   x = 1,231.81