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Finding the Fourth Proportional to 70.34, 105.57 and 31.88

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Solution

The fourth proportional to 70.34, 105.57 and 31.88 is: 47.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.34 : 105.57 = 31.88 : x
  2. Step 2: Convert to fraction form
    70.34/105.57 = 31.88/x
  3. Step 3: Cross multiply
    70.34x = 105.57 × 31.88
  4. Step 4: Simplify right side
    70.34x = 3,365.57
  5. Step 5: Solve for x
    x = 3,365.57/70.34
  6. Step 6: Final answer
    x = 47.85

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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.