Finding the Fourth Proportional to 78.50, 117.69 and 48.12

Step by Step Solution

1. Step 1: Write the proportion equation
   78.50 : 117.69 = 48.12 : x
2. Step 2: Convert to fraction form
   78.50/117.69 = 48.12/x
3. Step 3: Cross multiply
   78.50x = 117.69 × 48.12
4. Step 4: Simplify right side
   78.50x = 5,663.24
5. Step 5: Solve for x
   x = 5,663.24/78.50
6. Step 6: Final answer
   x = 72.15