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Finding the Fourth Proportional to 521.72, 782.71 and 213.80

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Solution

The fourth proportional to 521.72, 782.71 and 213.80 is: 320.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.72 : 782.71 = 213.80 : x
  2. Step 2: Convert to fraction form
    521.72/782.71 = 213.80/x
  3. Step 3: Cross multiply
    521.72x = 782.71 × 213.80
  4. Step 4: Simplify right side
    521.72x = 167,344.82
  5. Step 5: Solve for x
    x = 167,344.82/521.72
  6. Step 6: Final answer
    x = 320.76

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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.