Finding the Fourth Proportional to 100.58, 138.53 and 75.88

Step by Step Solution

1. Step 1: Write the proportion equation
   100.58 : 138.53 = 75.88 : x
2. Step 2: Convert to fraction form
   100.58/138.53 = 75.88/x
3. Step 3: Cross multiply
   100.58x = 138.53 × 75.88
4. Step 4: Simplify right side
   100.58x = 10,510.58
5. Step 5: Solve for x
   x = 10,510.58/100.58
6. Step 6: Final answer
   x = 104.50