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Finding the Third Proportional to 7.80 and 13.40

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Solution

The third proportional to 7.80 and 13.40 is: 23.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    7.80 : 13.40 = 13.40 : x
  2. Step 2: Convert to fraction form
    7.80/13.40 = 13.40/x
  3. Step 3: Cross multiply
    7.80x = 13.40 × 13.40
  4. Step 4: Simplify right side
    7.80x = 179.62
  5. Step 5: Solve for x
    x = 179.62/7.80
  6. Step 6: Final answer
    x = 23.01

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Why These Related Problems?

These problems maintain the same ratio (1.72) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.