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Finding the Fourth Proportional to 287.12, 431.49 and 279.83

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Solution

The fourth proportional to 287.12, 431.49 and 279.83 is: 420.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.12 : 431.49 = 279.83 : x
  2. Step 2: Convert to fraction form
    287.12/431.49 = 279.83/x
  3. Step 3: Cross multiply
    287.12x = 431.49 × 279.83
  4. Step 4: Simplify right side
    287.12x = 120,743.85
  5. Step 5: Solve for x
    x = 120,743.85/287.12
  6. Step 6: Final answer
    x = 420.53

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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.