Finding the Fourth Proportional to 1,111.82, 1,534.22 and 639.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.82 : 1,534.22 = 639.69 : x
2. Step 2: Convert to fraction form
   1,111.82/1,534.22 = 639.69/x
3. Step 3: Cross multiply
   1,111.82x = 1,534.22 × 639.69
4. Step 4: Simplify right side
   1,111.82x = 981,425.19
5. Step 5: Solve for x
   x = 981,425.19/1,111.82
6. Step 6: Final answer
   x = 882.72