Finding the Fourth Proportional to 2,646.86, 3,970.47 and 915.62

Step by Step Solution

1. Step 1: Write the proportion equation
   2,646.86 : 3,970.47 = 915.62 : x
2. Step 2: Convert to fraction form
   2,646.86/3,970.47 = 915.62/x
3. Step 3: Cross multiply
   2,646.86x = 3,970.47 × 915.62
4. Step 4: Simplify right side
   2,646.86x = 3,635,441.74
5. Step 5: Solve for x
   x = 3,635,441.74/2,646.86
6. Step 6: Final answer
   x = 1,373.49