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Finding the Fourth Proportional to 10.39, 15.61 and 7.88

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Solution

The fourth proportional to 10.39, 15.61 and 7.88 is: 11.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    10.39 : 15.61 = 7.88 : x
  2. Step 2: Convert to fraction form
    10.39/15.61 = 7.88/x
  3. Step 3: Cross multiply
    10.39x = 15.61 × 7.88
  4. Step 4: Simplify right side
    10.39x = 123.04
  5. Step 5: Solve for x
    x = 123.04/10.39
  6. Step 6: Final answer
    x = 11.84

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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.