Finding the Fourth Proportional to 1,009.68, 1,392.72 and 636.01

Step by Step Solution

1. Step 1: Write the proportion equation
   1,009.68 : 1,392.72 = 636.01 : x
2. Step 2: Convert to fraction form
   1,009.68/1,392.72 = 636.01/x
3. Step 3: Cross multiply
   1,009.68x = 1,392.72 × 636.01
4. Step 4: Simplify right side
   1,009.68x = 885,783.85
5. Step 5: Solve for x
   x = 885,783.85/1,009.68
6. Step 6: Final answer
   x = 877.29