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Finding the Fourth Proportional to 83.61, 115.17 and 71.31

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Solution

The fourth proportional to 83.61, 115.17 and 71.31 is: 98.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    83.61 : 115.17 = 71.31 : x
  2. Step 2: Convert to fraction form
    83.61/115.17 = 71.31/x
  3. Step 3: Cross multiply
    83.61x = 115.17 × 71.31
  4. Step 4: Simplify right side
    83.61x = 8,212.77
  5. Step 5: Solve for x
    x = 8,212.77/83.61
  6. Step 6: Final answer
    x = 98.23

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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.