Finding the Fourth Proportional to 2,123.61, 3,186.65 and 890.92

Step by Step Solution

1. Step 1: Write the proportion equation
   2,123.61 : 3,186.65 = 890.92 : x
2. Step 2: Convert to fraction form
   2,123.61/3,186.65 = 890.92/x
3. Step 3: Cross multiply
   2,123.61x = 3,186.65 × 890.92
4. Step 4: Simplify right side
   2,123.61x = 2,839,050.22
5. Step 5: Solve for x
   x = 2,839,050.22/2,123.61
6. Step 6: Final answer
   x = 1,336.90