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Finding the Fourth Proportional to 256.72, 383.28 and 215.71

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Solution

The fourth proportional to 256.72, 383.28 and 215.71 is: 322.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.72 : 383.28 = 215.71 : x
  2. Step 2: Convert to fraction form
    256.72/383.28 = 215.71/x
  3. Step 3: Cross multiply
    256.72x = 383.28 × 215.71
  4. Step 4: Simplify right side
    256.72x = 82,678.93
  5. Step 5: Solve for x
    x = 82,678.93/256.72
  6. Step 6: Final answer
    x = 322.06

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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.