Finding the Fourth Proportional to 1,021.60, 1,530.72 and 636.04

Step by Step Solution

1. Step 1: Write the proportion equation
   1,021.60 : 1,530.72 = 636.04 : x
2. Step 2: Convert to fraction form
   1,021.60/1,530.72 = 636.04/x
3. Step 3: Cross multiply
   1,021.60x = 1,530.72 × 636.04
4. Step 4: Simplify right side
   1,021.60x = 973,599.15
5. Step 5: Solve for x
   x = 973,599.15/1,021.60
6. Step 6: Final answer
   x = 953.01