Finding the Fourth Proportional to 939.69, 1,408.50 and 929.43

Step by Step Solution

1. Step 1: Write the proportion equation
   939.69 : 1,408.50 = 929.43 : x
2. Step 2: Convert to fraction form
   939.69/1,408.50 = 929.43/x
3. Step 3: Cross multiply
   939.69x = 1,408.50 × 929.43
4. Step 4: Simplify right side
   939.69x = 1,309,102.16
5. Step 5: Solve for x
   x = 1,309,102.16/939.69
6. Step 6: Final answer
   x = 1,393.12