Finding the Fourth Proportional to 1,106.50, 1,527.03 and 640.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,106.50 : 1,527.03 = 640.78 : x
2. Step 2: Convert to fraction form
   1,106.50/1,527.03 = 640.78/x
3. Step 3: Cross multiply
   1,106.50x = 1,527.03 × 640.78
4. Step 4: Simplify right side
   1,106.50x = 978,490.28
5. Step 5: Solve for x
   x = 978,490.28/1,106.50
6. Step 6: Final answer
   x = 884.31