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Finding the Fourth Proportional to 64.87, 97.20 and 47.70

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Solution

The fourth proportional to 64.87, 97.20 and 47.70 is: 71.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    64.87 : 97.20 = 47.70 : x
  2. Step 2: Convert to fraction form
    64.87/97.20 = 47.70/x
  3. Step 3: Cross multiply
    64.87x = 97.20 × 47.70
  4. Step 4: Simplify right side
    64.87x = 4,636.44
  5. Step 5: Solve for x
    x = 4,636.44/64.87
  6. Step 6: Final answer
    x = 71.47

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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.