Finding the Fourth Proportional to 1,144.50, 1,579.56 and 678.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,144.50 : 1,579.56 = 678.78 : x
2. Step 2: Convert to fraction form
   1,144.50/1,579.56 = 678.78/x
3. Step 3: Cross multiply
   1,144.50x = 1,579.56 × 678.78
4. Step 4: Simplify right side
   1,144.50x = 1,072,173.74
5. Step 5: Solve for x
   x = 1,072,173.74/1,144.50
6. Step 6: Final answer
   x = 936.81