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Finding the Third Proportional to 420.50 and 665

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Solution

The third proportional to 420.50 and 665 is: 1,051.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.50 : 665 = 665 : x
  2. Step 2: Convert to fraction form
    420.50/665 = 665/x
  3. Step 3: Cross multiply
    420.50x = 665 × 665
  4. Step 4: Simplify right side
    420.50x = 442,225
  5. Step 5: Solve for x
    x = 442,225/420.50
  6. Step 6: Final answer
    x = 1,051.66

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Why These Related Problems?

These problems maintain the same ratio (1.58) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.