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Finding the Fourth Proportional to 521.28, 781.90 and 247.60

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Solution

The fourth proportional to 521.28, 781.90 and 247.60 is: 371.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.28 : 781.90 = 247.60 : x
  2. Step 2: Convert to fraction form
    521.28/781.90 = 247.60/x
  3. Step 3: Cross multiply
    521.28x = 781.90 × 247.60
  4. Step 4: Simplify right side
    521.28x = 193,598.44
  5. Step 5: Solve for x
    x = 193,598.44/521.28
  6. Step 6: Final answer
    x = 371.39

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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.