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Finding the Fourth Proportional to 521.47, 782.21 and 330.31

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Solution

The fourth proportional to 521.47, 782.21 and 330.31 is: 495.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.47 : 782.21 = 330.31 : x
  2. Step 2: Convert to fraction form
    521.47/782.21 = 330.31/x
  3. Step 3: Cross multiply
    521.47x = 782.21 × 330.31
  4. Step 4: Simplify right side
    521.47x = 258,371.79
  5. Step 5: Solve for x
    x = 258,371.79/521.47
  6. Step 6: Final answer
    x = 495.47

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Double scale
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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.