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Finding the Fourth Proportional to 103.38, 142.68 and 71.92

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Solution

The fourth proportional to 103.38, 142.68 and 71.92 is: 99.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.38 : 142.68 = 71.92 : x
  2. Step 2: Convert to fraction form
    103.38/142.68 = 71.92/x
  3. Step 3: Cross multiply
    103.38x = 142.68 × 71.92
  4. Step 4: Simplify right side
    103.38x = 10,261.55
  5. Step 5: Solve for x
    x = 10,261.55/103.38
  6. Step 6: Final answer
    x = 99.26

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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.