Finding the Fourth Proportional to 1,071.77, 1,478.98 and 678.92

Step by Step Solution

1. Step 1: Write the proportion equation
   1,071.77 : 1,478.98 = 678.92 : x
2. Step 2: Convert to fraction form
   1,071.77/1,478.98 = 678.92/x
3. Step 3: Cross multiply
   1,071.77x = 1,478.98 × 678.92
4. Step 4: Simplify right side
   1,071.77x = 1,004,111.10
5. Step 5: Solve for x
   x = 1,004,111.10/1,071.77
6. Step 6: Final answer
   x = 936.87