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Finding the Third Proportional to 278 and 415

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Solution

The third proportional to 278 and 415 is: 619.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    278 : 415 = 415 : x
  2. Step 2: Convert to fraction form
    278/415 = 415/x
  3. Step 3: Cross multiply
    278x = 415 × 415
  4. Step 4: Simplify right side
    278x = 172,225
  5. Step 5: Solve for x
    x = 172,225/278
  6. Step 6: Final answer
    x = 619.51

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.