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Finding the Third Proportional to 15.75 and 21.38

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Solution

The third proportional to 15.75 and 21.38 is: 29.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.75 : 21.38 = 21.38 : x
  2. Step 2: Convert to fraction form
    15.75/21.38 = 21.38/x
  3. Step 3: Cross multiply
    15.75x = 21.38 × 21.38
  4. Step 4: Simplify right side
    15.75x = 456.89
  5. Step 5: Solve for x
    x = 456.89/15.75
  6. Step 6: Final answer
    x = 29.01

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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.