Finding the Fourth Proportional to 1,390.91, 2,084.98 and 774.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.91 : 2,084.98 = 774.89 : x
2. Step 2: Convert to fraction form
   1,390.91/2,084.98 = 774.89/x
3. Step 3: Cross multiply
   1,390.91x = 2,084.98 × 774.89
4. Step 4: Simplify right side
   1,390.91x = 1,615,630.15
5. Step 5: Solve for x
   x = 1,615,630.15/1,390.91
6. Step 6: Final answer
   x = 1,161.56