Finding the Fourth Proportional to 1,071.56, 1,478.96 and 629.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,071.56 : 1,478.96 = 629.71 : x
2. Step 2: Convert to fraction form
   1,071.56/1,478.96 = 629.71/x
3. Step 3: Cross multiply
   1,071.56x = 1,478.96 × 629.71
4. Step 4: Simplify right side
   1,071.56x = 931,311.42
5. Step 5: Solve for x
   x = 931,311.42/1,071.56
6. Step 6: Final answer
   x = 869.12