Finding the Fourth Proportional to 1,071.50, 1,478.76 and 678.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,071.50 : 1,478.76 = 678.83 : x
2. Step 2: Convert to fraction form
   1,071.50/1,478.76 = 678.83/x
3. Step 3: Cross multiply
   1,071.50x = 1,478.76 × 678.83
4. Step 4: Simplify right side
   1,071.50x = 1,003,826.65
5. Step 5: Solve for x
   x = 1,003,826.65/1,071.50
6. Step 6: Final answer
   x = 936.84