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Finding the Fourth Proportional to 256.32, 386.21 and 213.92

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Solution

The fourth proportional to 256.32, 386.21 and 213.92 is: 322.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.32 : 386.21 = 213.92 : x
  2. Step 2: Convert to fraction form
    256.32/386.21 = 213.92/x
  3. Step 3: Cross multiply
    256.32x = 386.21 × 213.92
  4. Step 4: Simplify right side
    256.32x = 82,618.04
  5. Step 5: Solve for x
    x = 82,618.04/256.32
  6. Step 6: Final answer
    x = 322.32

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.