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Finding the Fourth Proportional to 278.20, 383.90 and 153.85

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Solution

The fourth proportional to 278.20, 383.90 and 153.85 is: 212.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.20 : 383.90 = 153.85 : x
  2. Step 2: Convert to fraction form
    278.20/383.90 = 153.85/x
  3. Step 3: Cross multiply
    278.20x = 383.90 × 153.85
  4. Step 4: Simplify right side
    278.20x = 59,062.25
  5. Step 5: Solve for x
    x = 59,062.25/278.20
  6. Step 6: Final answer
    x = 212.31

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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.