Finding the Fourth Proportional to 1,008.52, 1,390.56 and 915.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,008.52 : 1,390.56 = 915.28 : x
2. Step 2: Convert to fraction form
   1,008.52/1,390.56 = 915.28/x
3. Step 3: Cross multiply
   1,008.52x = 1,390.56 × 915.28
4. Step 4: Simplify right side
   1,008.52x = 1,272,751.76
5. Step 5: Solve for x
   x = 1,272,751.76/1,008.52
6. Step 6: Final answer
   x = 1,262.00