Finding the Fourth Proportional to 78.93, 109.01 and 78.12

Step by Step Solution

1. Step 1: Write the proportion equation
   78.93 : 109.01 = 78.12 : x
2. Step 2: Convert to fraction form
   78.93/109.01 = 78.12/x
3. Step 3: Cross multiply
   78.93x = 109.01 × 78.12
4. Step 4: Simplify right side
   78.93x = 8,516.06
5. Step 5: Solve for x
   x = 8,516.06/78.93
6. Step 6: Final answer
   x = 107.89