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Finding the Fourth Proportional to 212.78, 319.27 and 120.17

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Solution

The fourth proportional to 212.78, 319.27 and 120.17 is: 180.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.78 : 319.27 = 120.17 : x
  2. Step 2: Convert to fraction form
    212.78/319.27 = 120.17/x
  3. Step 3: Cross multiply
    212.78x = 319.27 × 120.17
  4. Step 4: Simplify right side
    212.78x = 38,366.68
  5. Step 5: Solve for x
    x = 38,366.68/212.78
  6. Step 6: Final answer
    x = 180.31

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.