Finding the Fourth Proportional to 2,621.60, 3,932.24 and 890.24

Step by Step Solution

1. Step 1: Write the proportion equation
   2,621.60 : 3,932.24 = 890.24 : x
2. Step 2: Convert to fraction form
   2,621.60/3,932.24 = 890.24/x
3. Step 3: Cross multiply
   2,621.60x = 3,932.24 × 890.24
4. Step 4: Simplify right side
   2,621.60x = 3,500,637.34
5. Step 5: Solve for x
   x = 3,500,637.34/2,621.60
6. Step 6: Final answer
   x = 1,335.31