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Finding the Fourth Proportional to 278.78, 418.19 and 141.65

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Solution

The fourth proportional to 278.78, 418.19 and 141.65 is: 212.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.78 : 418.19 = 141.65 : x
  2. Step 2: Convert to fraction form
    278.78/418.19 = 141.65/x
  3. Step 3: Cross multiply
    278.78x = 418.19 × 141.65
  4. Step 4: Simplify right side
    278.78x = 59,233.81
  5. Step 5: Solve for x
    x = 59,233.81/278.78
  6. Step 6: Final answer
    x = 212.47

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.