Finding the Fourth Proportional to 1,221.69, 1,685.91 and 697.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,221.69 : 1,685.91 = 697.82 : x
2. Step 2: Convert to fraction form
   1,221.69/1,685.91 = 697.82/x
3. Step 3: Cross multiply
   1,221.69x = 1,685.91 × 697.82
4. Step 4: Simplify right side
   1,221.69x = 1,176,465.39
5. Step 5: Solve for x
   x = 1,176,465.39/1,221.69
6. Step 6: Final answer
   x = 962.98