Finding the Fourth Proportional to 1,070.78, 1,477.69 and 628.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,070.78 : 1,477.69 = 628.69 : x
2. Step 2: Convert to fraction form
   1,070.78/1,477.69 = 628.69/x
3. Step 3: Cross multiply
   1,070.78x = 1,477.69 × 628.69
4. Step 4: Simplify right side
   1,070.78x = 929,006.43
5. Step 5: Solve for x
   x = 929,006.43/1,070.78
6. Step 6: Final answer
   x = 867.60