Finding the Fourth Proportional to 1,106.90, 1,527.27 and 640.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,106.90 : 1,527.27 = 640.88 : x
2. Step 2: Convert to fraction form
   1,106.90/1,527.27 = 640.88/x
3. Step 3: Cross multiply
   1,106.90x = 1,527.27 × 640.88
4. Step 4: Simplify right side
   1,106.90x = 978,789.16
5. Step 5: Solve for x
   x = 978,789.16/1,106.90
6. Step 6: Final answer
   x = 884.27