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Finding the Fourth Proportional to 83.54, 115.12 and 71.21

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Solution

The fourth proportional to 83.54, 115.12 and 71.21 is: 98.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    83.54 : 115.12 = 71.21 : x
  2. Step 2: Convert to fraction form
    83.54/115.12 = 71.21/x
  3. Step 3: Cross multiply
    83.54x = 115.12 × 71.21
  4. Step 4: Simplify right side
    83.54x = 8,197.70
  5. Step 5: Solve for x
    x = 8,197.70/83.54
  6. Step 6: Final answer
    x = 98.13

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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.