Finding the Fourth Proportional to 1,620.72, 2,429.40 and 890.04

Step by Step Solution

1. Step 1: Write the proportion equation
   1,620.72 : 2,429.40 = 890.04 : x
2. Step 2: Convert to fraction form
   1,620.72/2,429.40 = 890.04/x
3. Step 3: Cross multiply
   1,620.72x = 2,429.40 × 890.04
4. Step 4: Simplify right side
   1,620.72x = 2,162,263.18
5. Step 5: Solve for x
   x = 2,162,263.18/1,620.72
6. Step 6: Final answer
   x = 1,334.14