Finding the Fourth Proportional to 1,386.53, 1,913.24 and 915.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,386.53 : 1,913.24 = 915.34 : x
2. Step 2: Convert to fraction form
   1,386.53/1,913.24 = 915.34/x
3. Step 3: Cross multiply
   1,386.53x = 1,913.24 × 915.34
4. Step 4: Simplify right side
   1,386.53x = 1,751,261.05
5. Step 5: Solve for x
   x = 1,751,261.05/1,386.53
6. Step 6: Final answer
   x = 1,263.05