Finding the Fourth Proportional to 1,106.56, 1,526.96 and 640.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,106.56 : 1,526.96 = 640.72 : x
2. Step 2: Convert to fraction form
   1,106.56/1,526.96 = 640.72/x
3. Step 3: Cross multiply
   1,106.56x = 1,526.96 × 640.72
4. Step 4: Simplify right side
   1,106.56x = 978,353.81
5. Step 5: Solve for x
   x = 978,353.81/1,106.56
6. Step 6: Final answer
   x = 884.14