Finding the Fourth Proportional to 1,071.90, 1,478.25 and 678.24

Step by Step Solution

1. Step 1: Write the proportion equation
   1,071.90 : 1,478.25 = 678.24 : x
2. Step 2: Convert to fraction form
   1,071.90/1,478.25 = 678.24/x
3. Step 3: Cross multiply
   1,071.90x = 1,478.25 × 678.24
4. Step 4: Simplify right side
   1,071.90x = 1,002,608.28
5. Step 5: Solve for x
   x = 1,002,608.28/1,071.90
6. Step 6: Final answer
   x = 935.36