Finding the Fourth Proportional to 78.84, 117.59 and 67.50

Step by Step Solution

1. Step 1: Write the proportion equation
   78.84 : 117.59 = 67.50 : x
2. Step 2: Convert to fraction form
   78.84/117.59 = 67.50/x
3. Step 3: Cross multiply
   78.84x = 117.59 × 67.50
4. Step 4: Simplify right side
   78.84x = 7,936.99
5. Step 5: Solve for x
   x = 7,936.99/78.84
6. Step 6: Final answer
   x = 100.67