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Finding the Fourth Proportional to 521.26, 781.89 and 491.20

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Solution

The fourth proportional to 521.26, 781.89 and 491.20 is: 736.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.26 : 781.89 = 491.20 : x
  2. Step 2: Convert to fraction form
    521.26/781.89 = 491.20/x
  3. Step 3: Cross multiply
    521.26x = 781.89 × 491.20
  4. Step 4: Simplify right side
    521.26x = 384,064.37
  5. Step 5: Solve for x
    x = 384,064.37/521.26
  6. Step 6: Final answer
    x = 736.80

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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.