Finding the Fourth Proportional to 1,160.32, 1,601.28 and 636.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,160.32 : 1,601.28 = 636.40 : x
2. Step 2: Convert to fraction form
   1,160.32/1,601.28 = 636.40/x
3. Step 3: Cross multiply
   1,160.32x = 1,601.28 × 636.40
4. Step 4: Simplify right side
   1,160.32x = 1,019,054.59
5. Step 5: Solve for x
   x = 1,019,054.59/1,160.32
6. Step 6: Final answer
   x = 878.25