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Finding the Fourth Proportional to 103.27, 142.40 and 72.20

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Solution

The fourth proportional to 103.27, 142.40 and 72.20 is: 99.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.27 : 142.40 = 72.20 : x
  2. Step 2: Convert to fraction form
    103.27/142.40 = 72.20/x
  3. Step 3: Cross multiply
    103.27x = 142.40 × 72.20
  4. Step 4: Simplify right side
    103.27x = 10,281.27
  5. Step 5: Solve for x
    x = 10,281.27/103.27
  6. Step 6: Final answer
    x = 99.56

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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.