Finding the Fourth Proportional to 1,072.02, 1,478.72 and 678.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,072.02 : 1,478.72 = 678.76 : x
2. Step 2: Convert to fraction form
   1,072.02/1,478.72 = 678.76/x
3. Step 3: Cross multiply
   1,072.02x = 1,478.72 × 678.76
4. Step 4: Simplify right side
   1,072.02x = 1,003,695.99
5. Step 5: Solve for x
   x = 1,003,695.99/1,072.02
6. Step 6: Final answer
   x = 936.27