Finding the Fourth Proportional to 1,164.32, 1,606.72 and 640.35

Step by Step Solution

1. Step 1: Write the proportion equation
   1,164.32 : 1,606.72 = 640.35 : x
2. Step 2: Convert to fraction form
   1,164.32/1,606.72 = 640.35/x
3. Step 3: Cross multiply
   1,164.32x = 1,606.72 × 640.35
4. Step 4: Simplify right side
   1,164.32x = 1,028,863.15
5. Step 5: Solve for x
   x = 1,028,863.15/1,164.32
6. Step 6: Final answer
   x = 883.66