Finding the Fourth Proportional to 1,034.86, 1,428.06 and 641.92

Step by Step Solution

1. Step 1: Write the proportion equation
   1,034.86 : 1,428.06 = 641.92 : x
2. Step 2: Convert to fraction form
   1,034.86/1,428.06 = 641.92/x
3. Step 3: Cross multiply
   1,034.86x = 1,428.06 × 641.92
4. Step 4: Simplify right side
   1,034.86x = 916,700.28
5. Step 5: Solve for x
   x = 916,700.28/1,034.86
6. Step 6: Final answer
   x = 885.82