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Finding the Fourth Proportional to 39.21, 53.85 and 39.09

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Solution

The fourth proportional to 39.21, 53.85 and 39.09 is: 53.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    39.21 : 53.85 = 39.09 : x
  2. Step 2: Convert to fraction form
    39.21/53.85 = 39.09/x
  3. Step 3: Cross multiply
    39.21x = 53.85 × 39.09
  4. Step 4: Simplify right side
    39.21x = 2,105.00
  5. Step 5: Solve for x
    x = 2,105.00/39.21
  6. Step 6: Final answer
    x = 53.69

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.