Finding the Fourth Proportional to 1,164.18, 1,606.59 and 640.23

Step by Step Solution

1. Step 1: Write the proportion equation
   1,164.18 : 1,606.59 = 640.23 : x
2. Step 2: Convert to fraction form
   1,164.18/1,606.59 = 640.23/x
3. Step 3: Cross multiply
   1,164.18x = 1,606.59 × 640.23
4. Step 4: Simplify right side
   1,164.18x = 1,028,587.12
5. Step 5: Solve for x
   x = 1,028,587.12/1,164.18
6. Step 6: Final answer
   x = 883.53