Finding the Third Proportional to 258,196 and 391,158

Step by Step Solution

1. Step 1: Write the proportion equation
   258,196 : 391,158 = 391,158 : x
2. Step 2: Convert to fraction form
   258,196/391,158 = 391,158/x
3. Step 3: Cross multiply
   258,196x = 391,158 × 391,158
4. Step 4: Simplify right side
   258,196x = 153,004,580,964
5. Step 5: Solve for x
   x = 153,004,580,964/258,196
6. Step 6: Final answer
   x = 592,590.83