Finding the Fourth Proportional to 2,649.72, 3,970.14 and 1,915.56

Step by Step Solution

1. Step 1: Write the proportion equation
   2,649.72 : 3,970.14 = 1,915.56 : x
2. Step 2: Convert to fraction form
   2,649.72/3,970.14 = 1,915.56/x
3. Step 3: Cross multiply
   2,649.72x = 3,970.14 × 1,915.56
4. Step 4: Simplify right side
   2,649.72x = 7,605,041.38
5. Step 5: Solve for x
   x = 7,605,041.38/2,649.72
6. Step 6: Final answer
   x = 2,870.13