Finding the Third Proportional to 238.78 and 383.91

Step by Step Solution

1. Step 1: Write the proportion equation
   238.78 : 383.91 = 383.91 : x
2. Step 2: Convert to fraction form
   238.78/383.91 = 383.91/x
3. Step 3: Cross multiply
   238.78x = 383.91 × 383.91
4. Step 4: Simplify right side
   238.78x = 147,384.01
5. Step 5: Solve for x
   x = 147,384.01/238.78
6. Step 6: Final answer
   x = 617.23