Finding the Fourth Proportional to 1,615.04, 2,228.72 and 916.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,615.04 : 2,228.72 = 916.40 : x
2. Step 2: Convert to fraction form
   1,615.04/2,228.72 = 916.40/x
3. Step 3: Cross multiply
   1,615.04x = 2,228.72 × 916.40
4. Step 4: Simplify right side
   1,615.04x = 2,042,399.01
5. Step 5: Solve for x
   x = 2,042,399.01/1,615.04
6. Step 6: Final answer
   x = 1,264.61