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Finding the Third Proportional to 428 and 817

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Solution

The third proportional to 428 and 817 is: 1,559.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    428 : 817 = 817 : x
  2. Step 2: Convert to fraction form
    428/817 = 817/x
  3. Step 3: Cross multiply
    428x = 817 × 817
  4. Step 4: Simplify right side
    428x = 667,489
  5. Step 5: Solve for x
    x = 667,489/428
  6. Step 6: Final answer
    x = 1,559.55

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Why These Related Problems?

These problems maintain the same ratio (1.91) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.