Finding the Fourth Proportional to 1,408.39, 1,942.89 and 911.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,408.39 : 1,942.89 = 911.86 : x
2. Step 2: Convert to fraction form
   1,408.39/1,942.89 = 911.86/x
3. Step 3: Cross multiply
   1,408.39x = 1,942.89 × 911.86
4. Step 4: Simplify right side
   1,408.39x = 1,771,635.40
5. Step 5: Solve for x
   x = 1,771,635.40/1,408.39
6. Step 6: Final answer
   x = 1,257.92