Finding the Fourth Proportional to 78.71, 117.99 and 67.50

Step by Step Solution

1. Step 1: Write the proportion equation
   78.71 : 117.99 = 67.50 : x
2. Step 2: Convert to fraction form
   78.71/117.99 = 67.50/x
3. Step 3: Cross multiply
   78.71x = 117.99 × 67.50
4. Step 4: Simplify right side
   78.71x = 7,964.33
5. Step 5: Solve for x
   x = 7,964.33/78.71
6. Step 6: Final answer
   x = 101.19