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Finding the Fourth Proportional to 10.58, 15.87 and 7.21

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Solution

The fourth proportional to 10.58, 15.87 and 7.21 is: 10.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    10.58 : 15.87 = 7.21 : x
  2. Step 2: Convert to fraction form
    10.58/15.87 = 7.21/x
  3. Step 3: Cross multiply
    10.58x = 15.87 × 7.21
  4. Step 4: Simplify right side
    10.58x = 114.38
  5. Step 5: Solve for x
    x = 114.38/10.58
  6. Step 6: Final answer
    x = 10.81

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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.