Finding the Fourth Proportional to 1,061.70, 1,465.22 and 642.07

Step by Step Solution

1. Step 1: Write the proportion equation
   1,061.70 : 1,465.22 = 642.07 : x
2. Step 2: Convert to fraction form
   1,061.70/1,465.22 = 642.07/x
3. Step 3: Cross multiply
   1,061.70x = 1,465.22 × 642.07
4. Step 4: Simplify right side
   1,061.70x = 940,777.24
5. Step 5: Solve for x
   x = 940,777.24/1,061.70
6. Step 6: Final answer
   x = 886.10