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Finding the Fourth Proportional to 255.70, 381.33 and 217.42

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Solution

The fourth proportional to 255.70, 381.33 and 217.42 is: 324.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    255.70 : 381.33 = 217.42 : x
  2. Step 2: Convert to fraction form
    255.70/381.33 = 217.42/x
  3. Step 3: Cross multiply
    255.70x = 381.33 × 217.42
  4. Step 4: Simplify right side
    255.70x = 82,908.77
  5. Step 5: Solve for x
    x = 82,908.77/255.70
  6. Step 6: Final answer
    x = 324.25

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.