Finding the Fourth Proportional to 1,387.17, 1,914.46 and 889.63

Step by Step Solution

1. Step 1: Write the proportion equation
   1,387.17 : 1,914.46 = 889.63 : x
2. Step 2: Convert to fraction form
   1,387.17/1,914.46 = 889.63/x
3. Step 3: Cross multiply
   1,387.17x = 1,914.46 × 889.63
4. Step 4: Simplify right side
   1,387.17x = 1,703,151.48
5. Step 5: Solve for x
   x = 1,703,151.48/1,387.17
6. Step 6: Final answer
   x = 1,227.79