Finding the Fourth Proportional to 1,061.60, 1,464.65 and 641.79

Step by Step Solution

1. Step 1: Write the proportion equation
   1,061.60 : 1,464.65 = 641.79 : x
2. Step 2: Convert to fraction form
   1,061.60/1,464.65 = 641.79/x
3. Step 3: Cross multiply
   1,061.60x = 1,464.65 × 641.79
4. Step 4: Simplify right side
   1,061.60x = 939,998.73
5. Step 5: Solve for x
   x = 939,998.73/1,061.60
6. Step 6: Final answer
   x = 885.46