Finding the Fourth Proportional to 1,216.72, 1,823.46 and 890.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,216.72 : 1,823.46 = 890.56 : x
2. Step 2: Convert to fraction form
   1,216.72/1,823.46 = 890.56/x
3. Step 3: Cross multiply
   1,216.72x = 1,823.46 × 890.56
4. Step 4: Simplify right side
   1,216.72x = 1,623,900.54
5. Step 5: Solve for x
   x = 1,623,900.54/1,216.72
6. Step 6: Final answer
   x = 1,334.65