Finding the Fourth Proportional to 1,578.82, 2,178.52 and 915.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,578.82 : 2,178.52 = 915.54 : x
2. Step 2: Convert to fraction form
   1,578.82/2,178.52 = 915.54/x
3. Step 3: Cross multiply
   1,578.82x = 2,178.52 × 915.54
4. Step 4: Simplify right side
   1,578.82x = 1,994,522.20
5. Step 5: Solve for x
   x = 1,994,522.20/1,578.82
6. Step 6: Final answer
   x = 1,263.30