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Finding the Fourth Proportional to 309.62, 424.87 and 281.78

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Solution

The fourth proportional to 309.62, 424.87 and 281.78 is: 386.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.62 : 424.87 = 281.78 : x
  2. Step 2: Convert to fraction form
    309.62/424.87 = 281.78/x
  3. Step 3: Cross multiply
    309.62x = 424.87 × 281.78
  4. Step 4: Simplify right side
    309.62x = 119,719.43
  5. Step 5: Solve for x
    x = 119,719.43/309.62
  6. Step 6: Final answer
    x = 386.66

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.