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Finding the Fourth Proportional to 144.72, 218.34 and 128.88

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Solution

The fourth proportional to 144.72, 218.34 and 128.88 is: 194.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    144.72 : 218.34 = 128.88 : x
  2. Step 2: Convert to fraction form
    144.72/218.34 = 128.88/x
  3. Step 3: Cross multiply
    144.72x = 218.34 × 128.88
  4. Step 4: Simplify right side
    144.72x = 28,139.66
  5. Step 5: Solve for x
    x = 28,139.66/144.72
  6. Step 6: Final answer
    x = 194.44

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.