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Finding the Fourth Proportional to 215.60, 323.48 and 85.61

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Solution

The fourth proportional to 215.60, 323.48 and 85.61 is: 128.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.60 : 323.48 = 85.61 : x
  2. Step 2: Convert to fraction form
    215.60/323.48 = 85.61/x
  3. Step 3: Cross multiply
    215.60x = 323.48 × 85.61
  4. Step 4: Simplify right side
    215.60x = 27,693.12
  5. Step 5: Solve for x
    x = 27,693.12/215.60
  6. Step 6: Final answer
    x = 128.45

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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.