Finding the Fourth Proportional to 1,500.78, 2,072.19 and 912.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,500.78 : 2,072.19 = 912.12 : x
2. Step 2: Convert to fraction form
   1,500.78/2,072.19 = 912.12/x
3. Step 3: Cross multiply
   1,500.78x = 2,072.19 × 912.12
4. Step 4: Simplify right side
   1,500.78x = 1,890,085.94
5. Step 5: Solve for x
   x = 1,890,085.94/1,500.78
6. Step 6: Final answer
   x = 1,259.40