Finding the Fourth Proportional to 1,612.31, 2,420.89 and 919.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,612.31 : 2,420.89 = 919.76 : x
2. Step 2: Convert to fraction form
   1,612.31/2,420.89 = 919.76/x
3. Step 3: Cross multiply
   1,612.31x = 2,420.89 × 919.76
4. Step 4: Simplify right side
   1,612.31x = 2,226,623.38
5. Step 5: Solve for x
   x = 2,226,623.38/1,612.31
6. Step 6: Final answer
   x = 1,381.02