Finding the Fourth Proportional to 78.47, 108.25 and 49.31

Step by Step Solution

1. Step 1: Write the proportion equation
   78.47 : 108.25 = 49.31 : x
2. Step 2: Convert to fraction form
   78.47/108.25 = 49.31/x
3. Step 3: Cross multiply
   78.47x = 108.25 × 49.31
4. Step 4: Simplify right side
   78.47x = 5,337.81
5. Step 5: Solve for x
   x = 5,337.81/78.47
6. Step 6: Final answer
   x = 68.02