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Finding the Fourth Proportional to 287.56, 428.21 and 280.68

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Solution

The fourth proportional to 287.56, 428.21 and 280.68 is: 417.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.56 : 428.21 = 280.68 : x
  2. Step 2: Convert to fraction form
    287.56/428.21 = 280.68/x
  3. Step 3: Cross multiply
    287.56x = 428.21 × 280.68
  4. Step 4: Simplify right side
    287.56x = 120,189.98
  5. Step 5: Solve for x
    x = 120,189.98/287.56
  6. Step 6: Final answer
    x = 417.96

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.