Finding the Fourth Proportional to 2,123.69, 3,186.77 and 890.99

Step by Step Solution

1. Step 1: Write the proportion equation
   2,123.69 : 3,186.77 = 890.99 : x
2. Step 2: Convert to fraction form
   2,123.69/3,186.77 = 890.99/x
3. Step 3: Cross multiply
   2,123.69x = 3,186.77 × 890.99
4. Step 4: Simplify right side
   2,123.69x = 2,839,359.81
5. Step 5: Solve for x
   x = 2,839,359.81/2,123.69
6. Step 6: Final answer
   x = 1,337.00