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Finding the Fourth Proportional to 67.78, 101.61 and 31.70

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Solution

The fourth proportional to 67.78, 101.61 and 31.70 is: 47.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    67.78 : 101.61 = 31.70 : x
  2. Step 2: Convert to fraction form
    67.78/101.61 = 31.70/x
  3. Step 3: Cross multiply
    67.78x = 101.61 × 31.70
  4. Step 4: Simplify right side
    67.78x = 3,221.04
  5. Step 5: Solve for x
    x = 3,221.04/67.78
  6. Step 6: Final answer
    x = 47.53

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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.