Finding the Fourth Proportional to 1,221.84, 1,683.72 and 801.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,221.84 : 1,683.72 = 801.72 : x
2. Step 2: Convert to fraction form
   1,221.84/1,683.72 = 801.72/x
3. Step 3: Cross multiply
   1,221.84x = 1,683.72 × 801.72
4. Step 4: Simplify right side
   1,221.84x = 1,349,872.00
5. Step 5: Solve for x
   x = 1,349,872.00/1,221.84
6. Step 6: Final answer
   x = 1,104.79