Finding the Fourth Proportional to 1,144.05, 1,578.80 and 646.67

Step by Step Solution

1. Step 1: Write the proportion equation
   1,144.05 : 1,578.80 = 646.67 : x
2. Step 2: Convert to fraction form
   1,144.05/1,578.80 = 646.67/x
3. Step 3: Cross multiply
   1,144.05x = 1,578.80 × 646.67
4. Step 4: Simplify right side
   1,144.05x = 1,020,967.75
5. Step 5: Solve for x
   x = 1,020,967.75/1,144.05
6. Step 6: Final answer
   x = 892.42