Finding the Fourth Proportional to 2,648.72, 3,970.64 and 916.13

Step by Step Solution

1. Step 1: Write the proportion equation
   2,648.72 : 3,970.64 = 916.13 : x
2. Step 2: Convert to fraction form
   2,648.72/3,970.64 = 916.13/x
3. Step 3: Cross multiply
   2,648.72x = 3,970.64 × 916.13
4. Step 4: Simplify right side
   2,648.72x = 3,637,597.99
5. Step 5: Solve for x
   x = 3,637,597.99/2,648.72
6. Step 6: Final answer
   x = 1,373.34