Finding the Fourth Proportional to 2,152.88, 2,971.38 and 1,221.38

Step by Step Solution

1. Step 1: Write the proportion equation
   2,152.88 : 2,971.38 = 1,221.38 : x
2. Step 2: Convert to fraction form
   2,152.88/2,971.38 = 1,221.38/x
3. Step 3: Cross multiply
   2,152.88x = 2,971.38 × 1,221.38
4. Step 4: Simplify right side
   2,152.88x = 3,629,169.25
5. Step 5: Solve for x
   x = 3,629,169.25/2,152.88
6. Step 6: Final answer
   x = 1,685.73