Finding the Fourth Proportional to 1,421.52, 1,961.47 and 890.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,421.52 : 1,961.47 = 890.15 : x
2. Step 2: Convert to fraction form
   1,421.52/1,961.47 = 890.15/x
3. Step 3: Cross multiply
   1,421.52x = 1,961.47 × 890.15
4. Step 4: Simplify right side
   1,421.52x = 1,745,993.83
5. Step 5: Solve for x
   x = 1,745,993.83/1,421.52
6. Step 6: Final answer
   x = 1,228.26