Finding the Fourth Proportional to 1,109.86, 1,663.68 and 915.46

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.86 : 1,663.68 = 915.46 : x
2. Step 2: Convert to fraction form
   1,109.86/1,663.68 = 915.46/x
3. Step 3: Cross multiply
   1,109.86x = 1,663.68 × 915.46
4. Step 4: Simplify right side
   1,109.86x = 1,523,032.49
5. Step 5: Solve for x
   x = 1,523,032.49/1,109.86
6. Step 6: Final answer
   x = 1,372.27