Finding the Fourth Proportional to 2,152.38, 2,970.64 and 1,221.42

Step by Step Solution

1. Step 1: Write the proportion equation
   2,152.38 : 2,970.64 = 1,221.42 : x
2. Step 2: Convert to fraction form
   2,152.38/2,970.64 = 1,221.42/x
3. Step 3: Cross multiply
   2,152.38x = 2,970.64 × 1,221.42
4. Step 4: Simplify right side
   2,152.38x = 3,628,399.11
5. Step 5: Solve for x
   x = 3,628,399.11/2,152.38
6. Step 6: Final answer
   x = 1,685.76