Finding the Fourth Proportional to 2,648.28, 3,972.45 and 916.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,648.28 : 3,972.45 = 916.50 : x
2. Step 2: Convert to fraction form
   2,648.28/3,972.45 = 916.50/x
3. Step 3: Cross multiply
   2,648.28x = 3,972.45 × 916.50
4. Step 4: Simplify right side
   2,648.28x = 3,640,750.43
5. Step 5: Solve for x
   x = 3,640,750.43/2,648.28
6. Step 6: Final answer
   x = 1,374.76