Finding the Fourth Proportional to 2,123.42, 3,186.36 and 890.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,123.42 : 3,186.36 = 890.72 : x
2. Step 2: Convert to fraction form
   2,123.42/3,186.36 = 890.72/x
3. Step 3: Cross multiply
   2,123.42x = 3,186.36 × 890.72
4. Step 4: Simplify right side
   2,123.42x = 2,838,154.58
5. Step 5: Solve for x
   x = 2,838,154.58/2,123.42
6. Step 6: Final answer
   x = 1,336.60