Finding the Fourth Proportional to 1,216.69, 1,678.77 and 774.43

Step by Step Solution

1. Step 1: Write the proportion equation
   1,216.69 : 1,678.77 = 774.43 : x
2. Step 2: Convert to fraction form
   1,216.69/1,678.77 = 774.43/x
3. Step 3: Cross multiply
   1,216.69x = 1,678.77 × 774.43
4. Step 4: Simplify right side
   1,216.69x = 1,300,089.85
5. Step 5: Solve for x
   x = 1,300,089.85/1,216.69
6. Step 6: Final answer
   x = 1,068.55