Finding the Fourth Proportional to 2,646.96, 3,970.89 and 915.18

Step by Step Solution

1. Step 1: Write the proportion equation
   2,646.96 : 3,970.89 = 915.18 : x
2. Step 2: Convert to fraction form
   2,646.96/3,970.89 = 915.18/x
3. Step 3: Cross multiply
   2,646.96x = 3,970.89 × 915.18
4. Step 4: Simplify right side
   2,646.96x = 3,634,079.11
5. Step 5: Solve for x
   x = 3,634,079.11/2,646.96
6. Step 6: Final answer
   x = 1,372.93