Finding the Fourth Proportional to 2,122.91, 3,185.61 and 890.23

Step by Step Solution

1. Step 1: Write the proportion equation
   2,122.91 : 3,185.61 = 890.23 : x
2. Step 2: Convert to fraction form
   2,122.91/3,185.61 = 890.23/x
3. Step 3: Cross multiply
   2,122.91x = 3,185.61 × 890.23
4. Step 4: Simplify right side
   2,122.91x = 2,835,925.59
5. Step 5: Solve for x
   x = 2,835,925.59/2,122.91
6. Step 6: Final answer
   x = 1,335.87