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Finding the Fourth Proportional to 283.20, 422.40 and 257.28

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Solution

The fourth proportional to 283.20, 422.40 and 257.28 is: 383.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    283.20 : 422.40 = 257.28 : x
  2. Step 2: Convert to fraction form
    283.20/422.40 = 257.28/x
  3. Step 3: Cross multiply
    283.20x = 422.40 × 257.28
  4. Step 4: Simplify right side
    283.20x = 108,675.07
  5. Step 5: Solve for x
    x = 108,675.07/283.20
  6. Step 6: Final answer
    x = 383.74

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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.