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Finding the Fourth Proportional to 47.70, 71.82 and 39.65

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Solution

The fourth proportional to 47.70, 71.82 and 39.65 is: 59.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    47.70 : 71.82 = 39.65 : x
  2. Step 2: Convert to fraction form
    47.70/71.82 = 39.65/x
  3. Step 3: Cross multiply
    47.70x = 71.82 × 39.65
  4. Step 4: Simplify right side
    47.70x = 2,847.30
  5. Step 5: Solve for x
    x = 2,847.30/47.70
  6. Step 6: Final answer
    x = 59.69

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.