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Finding the Fourth Proportional to 256.88, 384.78 and 213.46

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Solution

The fourth proportional to 256.88, 384.78 and 213.46 is: 319.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.88 : 384.78 = 213.46 : x
  2. Step 2: Convert to fraction form
    256.88/384.78 = 213.46/x
  3. Step 3: Cross multiply
    256.88x = 384.78 × 213.46
  4. Step 4: Simplify right side
    256.88x = 82,135.14
  5. Step 5: Solve for x
    x = 82,135.14/256.88
  6. Step 6: Final answer
    x = 319.74

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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.