Finding the Fourth Proportional to 1,005.95, 1,388.89 and 628.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,005.95 : 1,388.89 = 628.42 : x
2. Step 2: Convert to fraction form
   1,005.95/1,388.89 = 628.42/x
3. Step 3: Cross multiply
   1,005.95x = 1,388.89 × 628.42
4. Step 4: Simplify right side
   1,005.95x = 872,802.78
5. Step 5: Solve for x
   x = 872,802.78/1,005.95
6. Step 6: Final answer
   x = 867.64