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Finding the Third Proportional to 428 and 513

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Solution

The third proportional to 428 and 513 is: 614.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    428 : 513 = 513 : x
  2. Step 2: Convert to fraction form
    428/513 = 513/x
  3. Step 3: Cross multiply
    428x = 513 × 513
  4. Step 4: Simplify right side
    428x = 263,169
  5. Step 5: Solve for x
    x = 263,169/428
  6. Step 6: Final answer
    x = 614.88

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Why These Related Problems?

These problems maintain the same ratio (1.20) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.