Finding the Fourth Proportional to 78.38, 108.10 and 50.72

Step by Step Solution

1. Step 1: Write the proportion equation
   78.38 : 108.10 = 50.72 : x
2. Step 2: Convert to fraction form
   78.38/108.10 = 50.72/x
3. Step 3: Cross multiply
   78.38x = 108.10 × 50.72
4. Step 4: Simplify right side
   78.38x = 5,482.98
5. Step 5: Solve for x
   x = 5,482.98/78.38
6. Step 6: Final answer
   x = 69.96