Finding the Fourth Proportional to 1,221.27, 1,684.77 and 1,174.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,221.27 : 1,684.77 = 1,174.12 : x
2. Step 2: Convert to fraction form
   1,221.27/1,684.77 = 1,174.12/x
3. Step 3: Cross multiply
   1,221.27x = 1,684.77 × 1,174.12
4. Step 4: Simplify right side
   1,221.27x = 1,978,122.15
5. Step 5: Solve for x
   x = 1,978,122.15/1,221.27
6. Step 6: Final answer
   x = 1,619.73