Finding the Fourth Proportional to 1,578.32, 2,177.83 and 915.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,578.32 : 2,177.83 = 915.05 : x
2. Step 2: Convert to fraction form
   1,578.32/2,177.83 = 915.05/x
3. Step 3: Cross multiply
   1,578.32x = 2,177.83 × 915.05
4. Step 4: Simplify right side
   1,578.32x = 1,992,807.88
5. Step 5: Solve for x
   x = 1,992,807.88/1,578.32
6. Step 6: Final answer
   x = 1,262.61