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Finding the Fourth Proportional to 144.30, 215.29 and 128.91

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Solution

The fourth proportional to 144.30, 215.29 and 128.91 is: 192.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    144.30 : 215.29 = 128.91 : x
  2. Step 2: Convert to fraction form
    144.30/215.29 = 128.91/x
  3. Step 3: Cross multiply
    144.30x = 215.29 × 128.91
  4. Step 4: Simplify right side
    144.30x = 27,753.03
  5. Step 5: Solve for x
    x = 27,753.03/144.30
  6. Step 6: Final answer
    x = 192.33

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.