Finding the Fourth Proportional to 78.05, 107.69 and 53.45

Step by Step Solution

1. Step 1: Write the proportion equation
   78.05 : 107.69 = 53.45 : x
2. Step 2: Convert to fraction form
   78.05/107.69 = 53.45/x
3. Step 3: Cross multiply
   78.05x = 107.69 × 53.45
4. Step 4: Simplify right side
   78.05x = 5,756.03
5. Step 5: Solve for x
   x = 5,756.03/78.05
6. Step 6: Final answer
   x = 73.75