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Finding the Fourth Proportional to 278.90, 384.90 and 154.56

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Solution

The fourth proportional to 278.90, 384.90 and 154.56 is: 213.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.90 : 384.90 = 154.56 : x
  2. Step 2: Convert to fraction form
    278.90/384.90 = 154.56/x
  3. Step 3: Cross multiply
    278.90x = 384.90 × 154.56
  4. Step 4: Simplify right side
    278.90x = 59,490.14
  5. Step 5: Solve for x
    x = 59,490.14/278.90
  6. Step 6: Final answer
    x = 213.30

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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.