Finding the Fourth Proportional to 1,061.95, 1,465.22 and 642.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,061.95 : 1,465.22 = 642.55 : x
2. Step 2: Convert to fraction form
   1,061.95/1,465.22 = 642.55/x
3. Step 3: Cross multiply
   1,061.95x = 1,465.22 × 642.55
4. Step 4: Simplify right side
   1,061.95x = 941,477.11
5. Step 5: Solve for x
   x = 941,477.11/1,061.95
6. Step 6: Final answer
   x = 886.56