Finding the Fourth Proportional to 1,387.37, 1,914.89 and 890.43

Step by Step Solution

1. Step 1: Write the proportion equation
   1,387.37 : 1,914.89 = 890.43 : x
2. Step 2: Convert to fraction form
   1,387.37/1,914.89 = 890.43/x
3. Step 3: Cross multiply
   1,387.37x = 1,914.89 × 890.43
4. Step 4: Simplify right side
   1,387.37x = 1,705,071.05
5. Step 5: Solve for x
   x = 1,705,071.05/1,387.37
6. Step 6: Final answer
   x = 1,229.00