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Finding the Fourth Proportional to 859.36, 1,289.72 and 311.69

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Solution

The fourth proportional to 859.36, 1,289.72 and 311.69 is: 467.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    859.36 : 1,289.72 = 311.69 : x
  2. Step 2: Convert to fraction form
    859.36/1,289.72 = 311.69/x
  3. Step 3: Cross multiply
    859.36x = 1,289.72 × 311.69
  4. Step 4: Simplify right side
    859.36x = 401,991.27
  5. Step 5: Solve for x
    x = 401,991.27/859.36
  6. Step 6: Final answer
    x = 467.78

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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.