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Finding the Fourth Proportional to 10.31, 15.39 and 9.18

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Solution

The fourth proportional to 10.31, 15.39 and 9.18 is: 13.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    10.31 : 15.39 = 9.18 : x
  2. Step 2: Convert to fraction form
    10.31/15.39 = 9.18/x
  3. Step 3: Cross multiply
    10.31x = 15.39 × 9.18
  4. Step 4: Simplify right side
    10.31x = 141.28
  5. Step 5: Solve for x
    x = 141.28/10.31
  6. Step 6: Final answer
    x = 13.70

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.