Finding the Fourth Proportional to 1,059.59, 1,462.28 and 639.93

Step by Step Solution

1. Step 1: Write the proportion equation
   1,059.59 : 1,462.28 = 639.93 : x
2. Step 2: Convert to fraction form
   1,059.59/1,462.28 = 639.93/x
3. Step 3: Cross multiply
   1,059.59x = 1,462.28 × 639.93
4. Step 4: Simplify right side
   1,059.59x = 935,758.44
5. Step 5: Solve for x
   x = 935,758.44/1,059.59
6. Step 6: Final answer
   x = 883.13