Finding the Fourth Proportional to 1,071.88, 1,479.41 and 678.63

Step by Step Solution

1. Step 1: Write the proportion equation
   1,071.88 : 1,479.41 = 678.63 : x
2. Step 2: Convert to fraction form
   1,071.88/1,479.41 = 678.63/x
3. Step 3: Cross multiply
   1,071.88x = 1,479.41 × 678.63
4. Step 4: Simplify right side
   1,071.88x = 1,003,961.22
5. Step 5: Solve for x
   x = 1,003,961.22/1,071.88
6. Step 6: Final answer
   x = 936.64