Finding the Fourth Proportional to 2,646.36, 3,969.72 and 915.12

Step by Step Solution

1. Step 1: Write the proportion equation
   2,646.36 : 3,969.72 = 915.12 : x
2. Step 2: Convert to fraction form
   2,646.36/3,969.72 = 915.12/x
3. Step 3: Cross multiply
   2,646.36x = 3,969.72 × 915.12
4. Step 4: Simplify right side
   2,646.36x = 3,632,770.17
5. Step 5: Solve for x
   x = 3,632,770.17/2,646.36
6. Step 6: Final answer
   x = 1,372.74