Finding the Fourth Proportional to 2,636.40, 3,953.86 and 992.04

Step by Step Solution

1. Step 1: Write the proportion equation
   2,636.40 : 3,953.86 = 992.04 : x
2. Step 2: Convert to fraction form
   2,636.40/3,953.86 = 992.04/x
3. Step 3: Cross multiply
   2,636.40x = 3,953.86 × 992.04
4. Step 4: Simplify right side
   2,636.40x = 3,922,387.27
5. Step 5: Solve for x
   x = 3,922,387.27/2,636.40
6. Step 6: Final answer
   x = 1,487.78