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Finding the Fourth Proportional to 521.56, 781.90 and 328.76

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Solution

The fourth proportional to 521.56, 781.90 and 328.76 is: 492.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.56 : 781.90 = 328.76 : x
  2. Step 2: Convert to fraction form
    521.56/781.90 = 328.76/x
  3. Step 3: Cross multiply
    521.56x = 781.90 × 328.76
  4. Step 4: Simplify right side
    521.56x = 257,057.44
  5. Step 5: Solve for x
    x = 257,057.44/521.56
  6. Step 6: Final answer
    x = 492.86

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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.