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Finding the Fourth Proportional to 288.20, 428.60 and 279.09

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Solution

The fourth proportional to 288.20, 428.60 and 279.09 is: 415.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    288.20 : 428.60 = 279.09 : x
  2. Step 2: Convert to fraction form
    288.20/428.60 = 279.09/x
  3. Step 3: Cross multiply
    288.20x = 428.60 × 279.09
  4. Step 4: Simplify right side
    288.20x = 119,618.67
  5. Step 5: Solve for x
    x = 119,618.67/288.20
  6. Step 6: Final answer
    x = 415.05

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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.