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Finding the Third Proportional to 287 and 389

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Solution

The third proportional to 287 and 389 is: 527.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    287 : 389 = 389 : x
  2. Step 2: Convert to fraction form
    287/389 = 389/x
  3. Step 3: Cross multiply
    287x = 389 × 389
  4. Step 4: Simplify right side
    287x = 151,321
  5. Step 5: Solve for x
    x = 151,321/287
  6. Step 6: Final answer
    x = 527.25

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Why These Related Problems?

These problems maintain the same ratio (1.36) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.