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Finding the Fourth Proportional to 521.03, 781.54 and 212.88

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Solution

The fourth proportional to 521.03, 781.54 and 212.88 is: 319.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.03 : 781.54 = 212.88 : x
  2. Step 2: Convert to fraction form
    521.03/781.54 = 212.88/x
  3. Step 3: Cross multiply
    521.03x = 781.54 × 212.88
  4. Step 4: Simplify right side
    521.03x = 166,374.24
  5. Step 5: Solve for x
    x = 166,374.24/521.03
  6. Step 6: Final answer
    x = 319.32

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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.