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Finding the Fourth Proportional to 521.14, 781.71 and 212.79

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Solution

The fourth proportional to 521.14, 781.71 and 212.79 is: 319.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.14 : 781.71 = 212.79 : x
  2. Step 2: Convert to fraction form
    521.14/781.71 = 212.79/x
  3. Step 3: Cross multiply
    521.14x = 781.71 × 212.79
  4. Step 4: Simplify right side
    521.14x = 166,340.07
  5. Step 5: Solve for x
    x = 166,340.07/521.14
  6. Step 6: Final answer
    x = 319.19

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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.