Finding the Fourth Proportional to 139.67, 209.10 and 101.15

Step by Step Solution

1. Step 1: Write the proportion equation
   139.67 : 209.10 = 101.15 : x
2. Step 2: Convert to fraction form
   139.67/209.10 = 101.15/x
3. Step 3: Cross multiply
   139.67x = 209.10 × 101.15
4. Step 4: Simplify right side
   139.67x = 21,150.47
5. Step 5: Solve for x
   x = 21,150.47/139.67
6. Step 6: Final answer
   x = 151.43