Finding the Fourth Proportional to 78.00, 117.00 and 42.00

Step by Step Solution

1. Step 1: Write the proportion equation
   78.00 : 117.00 = 42.00 : x
2. Step 2: Convert to fraction form
   78.00/117.00 = 42.00/x
3. Step 3: Cross multiply
   78.00x = 117.00 × 42.00
4. Step 4: Simplify right side
   78.00x = 4,913.21
5. Step 5: Solve for x
   x = 4,913.21/78.00
6. Step 6: Final answer
   x = 62.99