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Finding the Fourth Proportional to 39.70, 59.08 and 38.90

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Solution

The fourth proportional to 39.70, 59.08 and 38.90 is: 57.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    39.70 : 59.08 = 38.90 : x
  2. Step 2: Convert to fraction form
    39.70/59.08 = 38.90/x
  3. Step 3: Cross multiply
    39.70x = 59.08 × 38.90
  4. Step 4: Simplify right side
    39.70x = 2,298.21
  5. Step 5: Solve for x
    x = 2,298.21/39.70
  6. Step 6: Final answer
    x = 57.89

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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.