Finding the Fourth Proportional to 1,006.98, 1,510.89 and 642.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,006.98 : 1,510.89 = 642.48 : x
2. Step 2: Convert to fraction form
   1,006.98/1,510.89 = 642.48/x
3. Step 3: Cross multiply
   1,006.98x = 1,510.89 × 642.48
4. Step 4: Simplify right side
   1,006.98x = 970,716.61
5. Step 5: Solve for x
   x = 970,716.61/1,006.98
6. Step 6: Final answer
   x = 963.99