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Finding the Fourth Proportional to 501.20, 691.67 and 280.21

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Solution

The fourth proportional to 501.20, 691.67 and 280.21 is: 386.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    501.20 : 691.67 = 280.21 : x
  2. Step 2: Convert to fraction form
    501.20/691.67 = 280.21/x
  3. Step 3: Cross multiply
    501.20x = 691.67 × 280.21
  4. Step 4: Simplify right side
    501.20x = 193,812.85
  5. Step 5: Solve for x
    x = 193,812.85/501.20
  6. Step 6: Final answer
    x = 386.70

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.