Finding the Fourth Proportional to 2,152.83, 2,970.90 and 1,221.33

Step by Step Solution

1. Step 1: Write the proportion equation
   2,152.83 : 2,970.90 = 1,221.33 : x
2. Step 2: Convert to fraction form
   2,152.83/2,970.90 = 1,221.33/x
3. Step 3: Cross multiply
   2,152.83x = 2,970.90 × 1,221.33
4. Step 4: Simplify right side
   2,152.83x = 3,628,447.16
5. Step 5: Solve for x
   x = 3,628,447.16/2,152.83
6. Step 6: Final answer
   x = 1,685.43