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Finding the Fourth Proportional to 256.20, 381.80 and 248.78

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Solution

The fourth proportional to 256.20, 381.80 and 248.78 is: 370.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.20 : 381.80 = 248.78 : x
  2. Step 2: Convert to fraction form
    256.20/381.80 = 248.78/x
  3. Step 3: Cross multiply
    256.20x = 381.80 × 248.78
  4. Step 4: Simplify right side
    256.20x = 94,984.20
  5. Step 5: Solve for x
    x = 94,984.20/256.20
  6. Step 6: Final answer
    x = 370.74

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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.