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Finding the Fourth Proportional to 398.71, 598.22 and 213.61

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Solution

The fourth proportional to 398.71, 598.22 and 213.61 is: 320.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.71 : 598.22 = 213.61 : x
  2. Step 2: Convert to fraction form
    398.71/598.22 = 213.61/x
  3. Step 3: Cross multiply
    398.71x = 598.22 × 213.61
  4. Step 4: Simplify right side
    398.71x = 127,785.77
  5. Step 5: Solve for x
    x = 127,785.77/398.71
  6. Step 6: Final answer
    x = 320.50

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.