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Finding the Third Proportional to 1,290 and 3,489

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Solution

The third proportional to 1,290 and 3,489 is: 9,436.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,290 : 3,489 = 3,489 : x
  2. Step 2: Convert to fraction form
    1,290/3,489 = 3,489/x
  3. Step 3: Cross multiply
    1,290x = 3,489 × 3,489
  4. Step 4: Simplify right side
    1,290x = 12,173,121
  5. Step 5: Solve for x
    x = 12,173,121/1,290
  6. Step 6: Final answer
    x = 9,436.53

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Why These Related Problems?

These problems maintain the same ratio (2.70) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.