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Finding the Fourth Proportional to 215.96, 297.99 and 128.61

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Solution

The fourth proportional to 215.96, 297.99 and 128.61 is: 177.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.96 : 297.99 = 128.61 : x
  2. Step 2: Convert to fraction form
    215.96/297.99 = 128.61/x
  3. Step 3: Cross multiply
    215.96x = 297.99 × 128.61
  4. Step 4: Simplify right side
    215.96x = 38,324.49
  5. Step 5: Solve for x
    x = 38,324.49/215.96
  6. Step 6: Final answer
    x = 177.47

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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.