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Finding the Fourth Proportional to 14.15, 21.20 and 5.12

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Solution

The fourth proportional to 14.15, 21.20 and 5.12 is: 7.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    14.15 : 21.20 = 5.12 : x
  2. Step 2: Convert to fraction form
    14.15/21.20 = 5.12/x
  3. Step 3: Cross multiply
    14.15x = 21.20 × 5.12
  4. Step 4: Simplify right side
    14.15x = 108.58
  5. Step 5: Solve for x
    x = 108.58/14.15
  6. Step 6: Final answer
    x = 7.68

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.