Finding the Fourth Proportional to 1,007.94, 1,510.65 and 641.91

Step by Step Solution

1. Step 1: Write the proportion equation
   1,007.94 : 1,510.65 = 641.91 : x
2. Step 2: Convert to fraction form
   1,007.94/1,510.65 = 641.91/x
3. Step 3: Cross multiply
   1,007.94x = 1,510.65 × 641.91
4. Step 4: Simplify right side
   1,007.94x = 969,701.34
5. Step 5: Solve for x
   x = 969,701.34/1,007.94
6. Step 6: Final answer
   x = 962.06