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Finding the Fourth Proportional to 15.34, 21.15 and 12.89

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Solution

The fourth proportional to 15.34, 21.15 and 12.89 is: 17.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.34 : 21.15 = 12.89 : x
  2. Step 2: Convert to fraction form
    15.34/21.15 = 12.89/x
  3. Step 3: Cross multiply
    15.34x = 21.15 × 12.89
  4. Step 4: Simplify right side
    15.34x = 272.49
  5. Step 5: Solve for x
    x = 272.49/15.34
  6. Step 6: Final answer
    x = 17.76

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.