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Finding the Fourth Proportional to 70.72, 97.79 and 61.61

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Solution

The fourth proportional to 70.72, 97.79 and 61.61 is: 85.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.72 : 97.79 = 61.61 : x
  2. Step 2: Convert to fraction form
    70.72/97.79 = 61.61/x
  3. Step 3: Cross multiply
    70.72x = 97.79 × 61.61
  4. Step 4: Simplify right side
    70.72x = 6,024.94
  5. Step 5: Solve for x
    x = 6,024.94/70.72
  6. Step 6: Final answer
    x = 85.19

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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.