Finding the Fourth Proportional to 78.39, 117.60 and 42.33

Step by Step Solution

1. Step 1: Write the proportion equation
   78.39 : 117.60 = 42.33 : x
2. Step 2: Convert to fraction form
   78.39/117.60 = 42.33/x
3. Step 3: Cross multiply
   78.39x = 117.60 × 42.33
4. Step 4: Simplify right side
   78.39x = 4,978.01
5. Step 5: Solve for x
   x = 4,978.01/78.39
6. Step 6: Final answer
   x = 63.50