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Finding the Third Proportional to 645 and 830

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Solution

The third proportional to 645 and 830 is: 1,068.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    645 : 830 = 830 : x
  2. Step 2: Convert to fraction form
    645/830 = 830/x
  3. Step 3: Cross multiply
    645x = 830 × 830
  4. Step 4: Simplify right side
    645x = 688,900
  5. Step 5: Solve for x
    x = 688,900/645
  6. Step 6: Final answer
    x = 1,068.06

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Why These Related Problems?

These problems maintain the same ratio (1.29) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.