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Finding the Third Proportional to 290.63 and 643.69

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Solution

The third proportional to 290.63 and 643.69 is: 1,425.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.63 : 643.69 = 643.69 : x
  2. Step 2: Convert to fraction form
    290.63/643.69 = 643.69/x
  3. Step 3: Cross multiply
    290.63x = 643.69 × 643.69
  4. Step 4: Simplify right side
    290.63x = 414,333.60
  5. Step 5: Solve for x
    x = 414,333.60/290.63
  6. Step 6: Final answer
    x = 1,425.66

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Why These Related Problems?

These problems maintain the same ratio (2.21) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.