Finding the Fourth Proportional to 99.94, 149.78 and 42.15

Step by Step Solution

1. Step 1: Write the proportion equation
   99.94 : 149.78 = 42.15 : x
2. Step 2: Convert to fraction form
   99.94/149.78 = 42.15/x
3. Step 3: Cross multiply
   99.94x = 149.78 × 42.15
4. Step 4: Simplify right side
   99.94x = 6,313.23
5. Step 5: Solve for x
   x = 6,313.23/99.94
6. Step 6: Final answer
   x = 63.17