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Finding the Fourth Proportional to 47.40, 70.81 and 38.76

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Solution

The fourth proportional to 47.40, 70.81 and 38.76 is: 57.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    47.40 : 70.81 = 38.76 : x
  2. Step 2: Convert to fraction form
    47.40/70.81 = 38.76/x
  3. Step 3: Cross multiply
    47.40x = 70.81 × 38.76
  4. Step 4: Simplify right side
    47.40x = 2,744.60
  5. Step 5: Solve for x
    x = 2,744.60/47.40
  6. Step 6: Final answer
    x = 57.90

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.