Finding the Fourth Proportional to 1,621.78, 2,238.02 and 913.62

Step by Step Solution

1. Step 1: Write the proportion equation
   1,621.78 : 2,238.02 = 913.62 : x
2. Step 2: Convert to fraction form
   1,621.78/2,238.02 = 913.62/x
3. Step 3: Cross multiply
   1,621.78x = 2,238.02 × 913.62
4. Step 4: Simplify right side
   1,621.78x = 2,044,699.83
5. Step 5: Solve for x
   x = 2,044,699.83/1,621.78
6. Step 6: Final answer
   x = 1,260.78