Finding the Fourth Proportional to 1,216.17, 1,678.33 and 692.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,216.17 : 1,678.33 = 692.21 : x
2. Step 2: Convert to fraction form
   1,216.17/1,678.33 = 692.21/x
3. Step 3: Cross multiply
   1,216.17x = 1,678.33 × 692.21
4. Step 4: Simplify right side
   1,216.17x = 1,161,746.69
5. Step 5: Solve for x
   x = 1,161,746.69/1,216.17
6. Step 6: Final answer
   x = 955.25