Finding the Fourth Proportional to 1,636.47, 2,453.22 and 815.00

Step by Step Solution

1. Step 1: Write the proportion equation
   1,636.47 : 2,453.22 = 815.00 : x
2. Step 2: Convert to fraction form
   1,636.47/2,453.22 = 815.00/x
3. Step 3: Cross multiply
   1,636.47x = 2,453.22 × 815.00
4. Step 4: Simplify right side
   1,636.47x = 1,999,362.03
5. Step 5: Solve for x
   x = 1,999,362.03/1,636.47
6. Step 6: Final answer
   x = 1,221.75