Finding the Fourth Proportional to 2,153, 2,971.50 and 1,221.32

Step by Step Solution

1. Step 1: Write the proportion equation
   2,153 : 2,971.50 = 1,221.32 : x
2. Step 2: Convert to fraction form
   2,153/2,971.50 = 1,221.32/x
3. Step 3: Cross multiply
   2,153x = 2,971.50 × 1,221.32
4. Step 4: Simplify right side
   2,153x = 3,629,152.38
5. Step 5: Solve for x
   x = 3,629,152.38/2,153
6. Step 6: Final answer
   x = 1,685.63