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Finding the Fourth Proportional to 215.64, 297.59 and 128.30

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Solution

The fourth proportional to 215.64, 297.59 and 128.30 is: 177.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.64 : 297.59 = 128.30 : x
  2. Step 2: Convert to fraction form
    215.64/297.59 = 128.30/x
  3. Step 3: Cross multiply
    215.64x = 297.59 × 128.30
  4. Step 4: Simplify right side
    215.64x = 38,179.71
  5. Step 5: Solve for x
    x = 38,179.71/215.64
  6. Step 6: Final answer
    x = 177.05

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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.