Finding the Fourth Proportional to 99.63, 149.50 and 38.78

Step by Step Solution

1. Step 1: Write the proportion equation
   99.63 : 149.50 = 38.78 : x
2. Step 2: Convert to fraction form
   99.63/149.50 = 38.78/x
3. Step 3: Cross multiply
   99.63x = 149.50 × 38.78
4. Step 4: Simplify right side
   99.63x = 5,797.25
5. Step 5: Solve for x
   x = 5,797.25/99.63
6. Step 6: Final answer
   x = 58.19