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Finding the Fourth Proportional to 143.54, 215.31 and 71.31

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Solution

The fourth proportional to 143.54, 215.31 and 71.31 is: 106.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    143.54 : 215.31 = 71.31 : x
  2. Step 2: Convert to fraction form
    143.54/215.31 = 71.31/x
  3. Step 3: Cross multiply
    143.54x = 215.31 × 71.31
  4. Step 4: Simplify right side
    143.54x = 15,353.76
  5. Step 5: Solve for x
    x = 15,353.76/143.54
  6. Step 6: Final answer
    x = 106.97

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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.