Finding the Fourth Proportional to 76.69, 105.71 and 52.09

Step by Step Solution

1. Step 1: Write the proportion equation
   76.69 : 105.71 = 52.09 : x
2. Step 2: Convert to fraction form
   76.69/105.71 = 52.09/x
3. Step 3: Cross multiply
   76.69x = 105.71 × 52.09
4. Step 4: Simplify right side
   76.69x = 5,506.50
5. Step 5: Solve for x
   x = 5,506.50/76.69
6. Step 6: Final answer
   x = 71.80