Finding the Fourth Proportional to 1,017.47, 1,403.71 and 663.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,017.47 : 1,403.71 = 663.81 : x
2. Step 2: Convert to fraction form
   1,017.47/1,403.71 = 663.81/x
3. Step 3: Cross multiply
   1,017.47x = 1,403.71 × 663.81
4. Step 4: Simplify right side
   1,017.47x = 931,795.08
5. Step 5: Solve for x
   x = 931,795.08/1,017.47
6. Step 6: Final answer
   x = 915.79