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Finding the Fourth Proportional to 278.55, 384.39 and 154.20

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Solution

The fourth proportional to 278.55, 384.39 and 154.20 is: 212.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.55 : 384.39 = 154.20 : x
  2. Step 2: Convert to fraction form
    278.55/384.39 = 154.20/x
  3. Step 3: Cross multiply
    278.55x = 384.39 × 154.20
  4. Step 4: Simplify right side
    278.55x = 59,274.96
  5. Step 5: Solve for x
    x = 59,274.96/278.55
  6. Step 6: Final answer
    x = 212.80

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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.