Finding the Fourth Proportional to 1,387.59, 1,913.15 and 889.41

Step by Step Solution

1. Step 1: Write the proportion equation
   1,387.59 : 1,913.15 = 889.41 : x
2. Step 2: Convert to fraction form
   1,387.59/1,913.15 = 889.41/x
3. Step 3: Cross multiply
   1,387.59x = 1,913.15 × 889.41
4. Step 4: Simplify right side
   1,387.59x = 1,701,570.29
5. Step 5: Solve for x
   x = 1,701,570.29/1,387.59
6. Step 6: Final answer
   x = 1,226.28