Finding the Fourth Proportional to 2,635.48, 3,951.42 and 991.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,635.48 : 3,951.42 = 991.72 : x
2. Step 2: Convert to fraction form
   2,635.48/3,951.42 = 991.72/x
3. Step 3: Cross multiply
   2,635.48x = 3,951.42 × 991.72
4. Step 4: Simplify right side
   2,635.48x = 3,918,702.24
5. Step 5: Solve for x
   x = 3,918,702.24/2,635.48
6. Step 6: Final answer
   x = 1,486.90