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Finding the Fourth Proportional to 18.87, 28.28 and 9.72

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Solution

The fourth proportional to 18.87, 28.28 and 9.72 is: 14.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    18.87 : 28.28 = 9.72 : x
  2. Step 2: Convert to fraction form
    18.87/28.28 = 9.72/x
  3. Step 3: Cross multiply
    18.87x = 28.28 × 9.72
  4. Step 4: Simplify right side
    18.87x = 274.88
  5. Step 5: Solve for x
    x = 274.88/18.87
  6. Step 6: Final answer
    x = 14.57

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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.