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Finding the Third Proportional to 3.40 and 5.15

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Solution

The third proportional to 3.40 and 5.15 is: 7.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    3.40 : 5.15 = 5.15 : x
  2. Step 2: Convert to fraction form
    3.40/5.15 = 5.15/x
  3. Step 3: Cross multiply
    3.40x = 5.15 × 5.15
  4. Step 4: Simplify right side
    3.40x = 26.51
  5. Step 5: Solve for x
    x = 26.51/3.40
  6. Step 6: Final answer
    x = 7.80

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Why These Related Problems?

These problems maintain the same ratio (1.52) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.