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Finding the Fourth Proportional to 278.78, 384.75 and 154.49

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Solution

The fourth proportional to 278.78, 384.75 and 154.49 is: 213.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.78 : 384.75 = 154.49 : x
  2. Step 2: Convert to fraction form
    278.78/384.75 = 154.49/x
  3. Step 3: Cross multiply
    278.78x = 384.75 × 154.49
  4. Step 4: Simplify right side
    278.78x = 59,438.10
  5. Step 5: Solve for x
    x = 59,438.10/278.78
  6. Step 6: Final answer
    x = 213.21

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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.