Finding the Fourth Proportional to 78.75, 117.59 and 67.34

Step by Step Solution

1. Step 1: Write the proportion equation
   78.75 : 117.59 = 67.34 : x
2. Step 2: Convert to fraction form
   78.75/117.59 = 67.34/x
3. Step 3: Cross multiply
   78.75x = 117.59 × 67.34
4. Step 4: Simplify right side
   78.75x = 7,918.47
5. Step 5: Solve for x
   x = 7,918.47/78.75
6. Step 6: Final answer
   x = 100.55