Finding the Fourth Proportional to 78.34, 108.12 and 50.72

Step by Step Solution

1. Step 1: Write the proportion equation
   78.34 : 108.12 = 50.72 : x
2. Step 2: Convert to fraction form
   78.34/108.12 = 50.72/x
3. Step 3: Cross multiply
   78.34x = 108.12 × 50.72
4. Step 4: Simplify right side
   78.34x = 5,483.85
5. Step 5: Solve for x
   x = 5,483.85/78.34
6. Step 6: Final answer
   x = 70.00