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Finding the Third Proportional to 138 and 290

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Solution

The third proportional to 138 and 290 is: 609.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    138 : 290 = 290 : x
  2. Step 2: Convert to fraction form
    138/290 = 290/x
  3. Step 3: Cross multiply
    138x = 290 × 290
  4. Step 4: Simplify right side
    138x = 84,100
  5. Step 5: Solve for x
    x = 84,100/138
  6. Step 6: Final answer
    x = 609.42

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Why These Related Problems?

These problems maintain the same ratio (2.10) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.