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Finding the Fourth Proportional to 289.70, 400.38 and 231.38

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Solution

The fourth proportional to 289.70, 400.38 and 231.38 is: 319.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.70 : 400.38 = 231.38 : x
  2. Step 2: Convert to fraction form
    289.70/400.38 = 231.38/x
  3. Step 3: Cross multiply
    289.70x = 400.38 × 231.38
  4. Step 4: Simplify right side
    289.70x = 92,639.92
  5. Step 5: Solve for x
    x = 92,639.92/289.70
  6. Step 6: Final answer
    x = 319.78

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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.