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Finding the Fourth Proportional to 289.78, 399.61 and 191.36

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Solution

The fourth proportional to 289.78, 399.61 and 191.36 is: 263.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.78 : 399.61 = 191.36 : x
  2. Step 2: Convert to fraction form
    289.78/399.61 = 191.36/x
  3. Step 3: Cross multiply
    289.78x = 399.61 × 191.36
  4. Step 4: Simplify right side
    289.78x = 76,469.37
  5. Step 5: Solve for x
    x = 76,469.37/289.78
  6. Step 6: Final answer
    x = 263.89

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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.