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Finding the Fourth Proportional to 61, 91.39 and 39.28

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Solution

The fourth proportional to 61, 91.39 and 39.28 is: 58.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    61 : 91.39 = 39.28 : x
  2. Step 2: Convert to fraction form
    61/91.39 = 39.28/x
  3. Step 3: Cross multiply
    61x = 91.39 × 39.28
  4. Step 4: Simplify right side
    61x = 3,590.13
  5. Step 5: Solve for x
    x = 3,590.13/61
  6. Step 6: Final answer
    x = 58.85

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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.