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Finding the Third Proportional to 311.41 and 643.08

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Solution

The third proportional to 311.41 and 643.08 is: 1,327.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.41 : 643.08 = 643.08 : x
  2. Step 2: Convert to fraction form
    311.41/643.08 = 643.08/x
  3. Step 3: Cross multiply
    311.41x = 643.08 × 643.08
  4. Step 4: Simplify right side
    311.41x = 413,549.47
  5. Step 5: Solve for x
    x = 413,549.47/311.41
  6. Step 6: Final answer
    x = 1,327.97

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Why These Related Problems?

These problems maintain the same ratio (2.07) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.