Finding the Fourth Proportional to 123.69, 169.91 and 100.28

Step by Step Solution

1. Step 1: Write the proportion equation
   123.69 : 169.91 = 100.28 : x
2. Step 2: Convert to fraction form
   123.69/169.91 = 100.28/x
3. Step 3: Cross multiply
   123.69x = 169.91 × 100.28
4. Step 4: Simplify right side
   123.69x = 17,037.22
5. Step 5: Solve for x
   x = 17,037.22/123.69
6. Step 6: Final answer
   x = 137.74