Finding the Fourth Proportional to 1,222.35, 1,686.86 and 691.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,222.35 : 1,686.86 = 691.32 : x
2. Step 2: Convert to fraction form
   1,222.35/1,686.86 = 691.32/x
3. Step 3: Cross multiply
   1,222.35x = 1,686.86 × 691.32
4. Step 4: Simplify right side
   1,222.35x = 1,166,156.60
5. Step 5: Solve for x
   x = 1,166,156.60/1,222.35
6. Step 6: Final answer
   x = 954.03