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Finding the Fourth Proportional to 278.42, 384.21 and 154.09

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Solution

The fourth proportional to 278.42, 384.21 and 154.09 is: 212.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.42 : 384.21 = 154.09 : x
  2. Step 2: Convert to fraction form
    278.42/384.21 = 154.09/x
  3. Step 3: Cross multiply
    278.42x = 384.21 × 154.09
  4. Step 4: Simplify right side
    278.42x = 59,201.96
  5. Step 5: Solve for x
    x = 59,201.96/278.42
  6. Step 6: Final answer
    x = 212.63

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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.