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Finding the Third Proportional to 245 and 309

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Solution

The third proportional to 245 and 309 is: 389.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    245 : 309 = 309 : x
  2. Step 2: Convert to fraction form
    245/309 = 309/x
  3. Step 3: Cross multiply
    245x = 309 × 309
  4. Step 4: Simplify right side
    245x = 95,481
  5. Step 5: Solve for x
    x = 95,481/245
  6. Step 6: Final answer
    x = 389.72

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Why These Related Problems?

These problems maintain the same ratio (1.26) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.