Finding the Fourth Proportional to 1,164.78, 1,607.40 and 640.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,164.78 : 1,607.40 = 640.83 : x
2. Step 2: Convert to fraction form
   1,164.78/1,607.40 = 640.83/x
3. Step 3: Cross multiply
   1,164.78x = 1,607.40 × 640.83
4. Step 4: Simplify right side
   1,164.78x = 1,030,070.14
5. Step 5: Solve for x
   x = 1,030,070.14/1,164.78
6. Step 6: Final answer
   x = 884.35