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Finding the Fourth Proportional to 287.80, 397.18 and 217.74

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Solution

The fourth proportional to 287.80, 397.18 and 217.74 is: 300.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.80 : 397.18 = 217.74 : x
  2. Step 2: Convert to fraction form
    287.80/397.18 = 217.74/x
  3. Step 3: Cross multiply
    287.80x = 397.18 × 217.74
  4. Step 4: Simplify right side
    287.80x = 86,481.97
  5. Step 5: Solve for x
    x = 86,481.97/287.80
  6. Step 6: Final answer
    x = 300.49

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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.