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Finding the Fourth Proportional to 57.91, 86.89 and 47.20

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Solution

The fourth proportional to 57.91, 86.89 and 47.20 is: 70.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    57.91 : 86.89 = 47.20 : x
  2. Step 2: Convert to fraction form
    57.91/86.89 = 47.20/x
  3. Step 3: Cross multiply
    57.91x = 86.89 × 47.20
  4. Step 4: Simplify right side
    57.91x = 4,100.71
  5. Step 5: Solve for x
    x = 4,100.71/57.91
  6. Step 6: Final answer
    x = 70.82

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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.