Finding the Fourth Proportional to 1,117.72, 1,677.34 and 839.49

Step by Step Solution

1. Step 1: Write the proportion equation
   1,117.72 : 1,677.34 = 839.49 : x
2. Step 2: Convert to fraction form
   1,117.72/1,677.34 = 839.49/x
3. Step 3: Cross multiply
   1,117.72x = 1,677.34 × 839.49
4. Step 4: Simplify right side
   1,117.72x = 1,408,104.92
5. Step 5: Solve for x
   x = 1,408,104.92/1,117.72
6. Step 6: Final answer
   x = 1,259.80