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Finding the Fourth Proportional to 119.78, 164.85 and 105.20

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Solution

The fourth proportional to 119.78, 164.85 and 105.20 is: 144.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    119.78 : 164.85 = 105.20 : x
  2. Step 2: Convert to fraction form
    119.78/164.85 = 105.20/x
  3. Step 3: Cross multiply
    119.78x = 164.85 × 105.20
  4. Step 4: Simplify right side
    119.78x = 17,342.22
  5. Step 5: Solve for x
    x = 17,342.22/119.78
  6. Step 6: Final answer
    x = 144.78

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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.