Finding the Fourth Proportional to 1,175.22, 1,621.78 and 644.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,175.22 : 1,621.78 = 644.10 : x
2. Step 2: Convert to fraction form
   1,175.22/1,621.78 = 644.10/x
3. Step 3: Cross multiply
   1,175.22x = 1,621.78 × 644.10
4. Step 4: Simplify right side
   1,175.22x = 1,044,586.89
5. Step 5: Solve for x
   x = 1,044,586.89/1,175.22
6. Step 6: Final answer
   x = 888.85