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Finding the Fourth Proportional to 256.22, 384.95 and 213.20

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Solution

The fourth proportional to 256.22, 384.95 and 213.20 is: 320.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.22 : 384.95 = 213.20 : x
  2. Step 2: Convert to fraction form
    256.22/384.95 = 213.20/x
  3. Step 3: Cross multiply
    256.22x = 384.95 × 213.20
  4. Step 4: Simplify right side
    256.22x = 82,069.95
  5. Step 5: Solve for x
    x = 82,069.95/256.22
  6. Step 6: Final answer
    x = 320.32

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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.