Finding the Fourth Proportional to 2,156.31, 2,975.69 and 1,212.12

Step by Step Solution

1. Step 1: Write the proportion equation
   2,156.31 : 2,975.69 = 1,212.12 : x
2. Step 2: Convert to fraction form
   2,156.31/2,975.69 = 1,212.12/x
3. Step 3: Cross multiply
   2,156.31x = 2,975.69 × 1,212.12
4. Step 4: Simplify right side
   2,156.31x = 3,606,896.39
5. Step 5: Solve for x
   x = 3,606,896.39/2,156.31
6. Step 6: Final answer
   x = 1,672.72