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Finding the Fourth Proportional to 9.87, 13.62 and 5.72

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Solution

The fourth proportional to 9.87, 13.62 and 5.72 is: 7.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    9.87 : 13.62 = 5.72 : x
  2. Step 2: Convert to fraction form
    9.87/13.62 = 5.72/x
  3. Step 3: Cross multiply
    9.87x = 13.62 × 5.72
  4. Step 4: Simplify right side
    9.87x = 77.88
  5. Step 5: Solve for x
    x = 77.88/9.87
  6. Step 6: Final answer
    x = 7.89

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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.