Finding the Fourth Proportional to 639.72, 882.77 and 377.69

Step by Step Solution

1. Step 1: Write the proportion equation
   639.72 : 882.77 = 377.69 : x
2. Step 2: Convert to fraction form
   639.72/882.77 = 377.69/x
3. Step 3: Cross multiply
   639.72x = 882.77 × 377.69
4. Step 4: Simplify right side
   639.72x = 333,407.10
5. Step 5: Solve for x
   x = 333,407.10/639.72
6. Step 6: Final answer
   x = 521.18