Finding the Fourth Proportional to 1,010.59, 1,393.98 and 636.92

Step by Step Solution

1. Step 1: Write the proportion equation
   1,010.59 : 1,393.98 = 636.92 : x
2. Step 2: Convert to fraction form
   1,010.59/1,393.98 = 636.92/x
3. Step 3: Cross multiply
   1,010.59x = 1,393.98 × 636.92
4. Step 4: Simplify right side
   1,010.59x = 887,853.74
5. Step 5: Solve for x
   x = 887,853.74/1,010.59
6. Step 6: Final answer
   x = 878.55