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Finding the Fourth Proportional to 256.40, 382.15 and 256

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Solution

The fourth proportional to 256.40, 382.15 and 256 is: 381.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.40 : 382.15 = 256 : x
  2. Step 2: Convert to fraction form
    256.40/382.15 = 256/x
  3. Step 3: Cross multiply
    256.40x = 382.15 × 256
  4. Step 4: Simplify right side
    256.40x = 97,830.40
  5. Step 5: Solve for x
    x = 97,830.40/256.40
  6. Step 6: Final answer
    x = 381.55

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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.