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Finding the Fourth Proportional to 306.49, 422.70 and 213.40

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Solution

The fourth proportional to 306.49, 422.70 and 213.40 is: 294.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    306.49 : 422.70 = 213.40 : x
  2. Step 2: Convert to fraction form
    306.49/422.70 = 213.40/x
  3. Step 3: Cross multiply
    306.49x = 422.70 × 213.40
  4. Step 4: Simplify right side
    306.49x = 90,204.18
  5. Step 5: Solve for x
    x = 90,204.18/306.49
  6. Step 6: Final answer
    x = 294.31

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.