Finding the Fourth Proportional to 137.39, 189.56 and 100.56

Step by Step Solution

1. Step 1: Write the proportion equation
   137.39 : 189.56 = 100.56 : x
2. Step 2: Convert to fraction form
   137.39/189.56 = 100.56/x
3. Step 3: Cross multiply
   137.39x = 189.56 × 100.56
4. Step 4: Simplify right side
   137.39x = 19,061.65
5. Step 5: Solve for x
   x = 19,061.65/137.39
6. Step 6: Final answer
   x = 138.75