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Finding the Third Proportional to 215 and 490

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Solution

The third proportional to 215 and 490 is: 1,116.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    215 : 490 = 490 : x
  2. Step 2: Convert to fraction form
    215/490 = 490/x
  3. Step 3: Cross multiply
    215x = 490 × 490
  4. Step 4: Simplify right side
    215x = 240,100
  5. Step 5: Solve for x
    x = 240,100/215
  6. Step 6: Final answer
    x = 1,116.74

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Why These Related Problems?

These problems maintain the same ratio (2.28) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.