Finding the Fourth Proportional to 1,216.56, 1,678.82 and 692.64

Step by Step Solution

1. Step 1: Write the proportion equation
   1,216.56 : 1,678.82 = 692.64 : x
2. Step 2: Convert to fraction form
   1,216.56/1,678.82 = 692.64/x
3. Step 3: Cross multiply
   1,216.56x = 1,678.82 × 692.64
4. Step 4: Simplify right side
   1,216.56x = 1,162,817.88
5. Step 5: Solve for x
   x = 1,162,817.88/1,216.56
6. Step 6: Final answer
   x = 955.82