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Finding the Third Proportional to 280.49 and 643.81

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Solution

The third proportional to 280.49 and 643.81 is: 1,477.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.49 : 643.81 = 643.81 : x
  2. Step 2: Convert to fraction form
    280.49/643.81 = 643.81/x
  3. Step 3: Cross multiply
    280.49x = 643.81 × 643.81
  4. Step 4: Simplify right side
    280.49x = 414,488.25
  5. Step 5: Solve for x
    x = 414,488.25/280.49
  6. Step 6: Final answer
    x = 1,477.71

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Why These Related Problems?

These problems maintain the same ratio (2.30) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.