Finding the Fourth Proportional to 1,939.56, 2,912.16 and 1,212.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,939.56 : 2,912.16 = 1,212.12 : x
2. Step 2: Convert to fraction form
   1,939.56/2,912.16 = 1,212.12/x
3. Step 3: Cross multiply
   1,939.56x = 2,912.16 × 1,212.12
4. Step 4: Simplify right side
   1,939.56x = 3,529,887.38
5. Step 5: Solve for x
   x = 3,529,887.38/1,939.56
6. Step 6: Final answer
   x = 1,819.94