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Finding the Fourth Proportional to 61.89, 85.39 and 40.09

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Solution

The fourth proportional to 61.89, 85.39 and 40.09 is: 55.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    61.89 : 85.39 = 40.09 : x
  2. Step 2: Convert to fraction form
    61.89/85.39 = 40.09/x
  3. Step 3: Cross multiply
    61.89x = 85.39 × 40.09
  4. Step 4: Simplify right side
    61.89x = 3,423.29
  5. Step 5: Solve for x
    x = 3,423.29/61.89
  6. Step 6: Final answer
    x = 55.31

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.